Rapid flagella stain

Anaerobic flora, Selenomonas ruminis sp. nov., and the bacteriocinogenic Ligilactobacillus salivarius strain MP3 from crossbred-lactating goats

This study aimed to examine the distribution of anaerobic bacteria in the rumen fluid of Thai crossbred goats and to screen potential probiotic strains capable of producing antimicrobial compounds and inhibiting bacteria that cause milk fat depression. Thirty-four strains of bacteria from the rumen fluid were divided into 13 groups within 12 genera based on 16S rRNA gene sequences. The RF1-5 and RF5-12 were identified as Streptococcus luteliensis and Bacillus licheniformis, respectively, and demonstrated non-ropy exopolysaccharide. Furthermore, mPRGC5T was closely related to Selenomonas caprae JCM 33725 T (97.8% similarity) based on 16S rRNA gene sequences. It exhibited low average nucleotide identity, digital DNA-DNA hybridization, and average amino acid identity values with related type strains ranging from 84.9 to 86.0%, 21.3 to 21.8%, and 73.8 to 76.1%, respectively. The genotypic and phenotypic characteristics of mPRGC5T strongly support this strain as a new species of the genus Selenomonas for which the name Selenomonas ruminis mPRGC5T was proposed. The type strain is mPRGC5T (= JCM 33724 T = KCTC 25177 T). Ligilactobacillus salivarius MP3 showed antibacterial activity against Cutibacterium acnes subsp. acnes DSM 1897 T and Kocuria rhizophila MIII. The enterolysin A cluster gene was identified in its genome. The auto-aggregation of L. salivarius MP3 was 93.6 ± 0.2%. Additionally, co-aggregation of L. salivarius MP3 with C. acnes DSM 1897 T and K. rhizophila MIII had 92.2 ± 3.4% and 87.3 ± 4.5%, respectively. The adhesion capacity of strain MP3 was 76.11 ± 2.2%. Probiogenomic analysis revealed that L. salivarius MP3 was nonhazardous to animal supplementation and included acid- and bile-tolerant ability. However, strain MP3 contained three antibiotic resistance genes. Thus, the supplementation of L. salivarius MP3 could increase the milk fat content by suppressing C. acnes DSM 1897 T with antibiotic resistance gene horizontal transfer awareness.

Selenomonas caprae sp. nov., an obligately anaerobic and volatile fatty acid producing bacterium from ruminal fluid of domestic goat (Capra hircus L.)

A novel Gram-stain-negative, motile, obligately anaerobic bacterium strain mPRGC8^T was isolated from the ruminal fluid of a domestic goat (Capra hircus L.) in Nakhon Pathom province, Thailand. The strain grew at 20-45 °C (optimum, 37 °C), pH 6.0-9.0 (optimum, pH 7.5) and 3 % (w/v) NaCl. It produced acetate, propionate, valerate, caproate and heptanoate from glucose. The 16S rRNA gene sequence analysis indicated that strain mPRGC8^T belonged to the genus Selenomonas and was closely related to Selenomonas ruminantium subsp. ruminantium DSM 2150^T (98.0 %) and Selenomonas ruminantium subsp. lactilytica JCM 6582^T (97.9 %). The in silico DNA G+C content was 53.0 mol %. Strain mPRGC8^T showed average nucleotide identity, digital DNA-DNA hybridization and average animo acid identity values with Selenomonas montiformis JCM 34373^T, S. ruminantium subsp. lactilytica JCM 6582^T and S. ruminantium subsp. ruminantium DSM 2150^T ranging from 84.9 to 86.0 %, 21.3 to 21.8 % and 73.8 to 76.1 %, respectively. The predominant cellular fatty acids were C_16 : 1  ω9c and C_18 : 1  ω9c. Phosphatidylethanolamine, three unidentified aminophospholipids, two unidentified ninhydrin positive glycolipids, an unidentified phospholipid and an unidentified lipid were detected as polar lipids. The genomic and phenotypic characteristics of strain mPRGC8^T strongly support its classification as representative of new species of the genus Selenomonas for which the name Selenomonas caprae sp. nov. is proposed. The type strain is mPRGC8^T (=JCM 33725^T=KCTC 25178^T).

Weizmannia acidilactici sp. nov., a lactic acid producing bacterium isolated from soils

The strains designed PP-18^T, JC-4 and JC-7 isolated from soils, were Gram-stain-positive rods, facultative anaerobe, endospore-forming bacteria. The strains produced l-lactic acid from glucose. They showed positive for catalase but negative for oxidase, nitrate reduction and arginine hydrolysis. Strains P-18^T, JC-4 and JC-7 were closely related to Weizmannia coagulans LMG 6326^T (97.27-97.64%) and W. acidiproducens KCTC 13078^T (96.46-96.74%) based on 16S rRNA gene sequence similarity, respectively. They contained meso-diaminopimelic acid in cell wall peptidoglycan and had seven isoprene units (MK-7) as the predominant menaquinone. The major cellular fatty acids of strain PP-18^T were iso-C_15:0, anteiso-C_17:0, iso-C_16:0 and anteiso-C_15:0. The ANIb and ANIm values among the genomes of strains PP-18^T, JC-4 and JC-7 are above 99.4% while their ANIb and ANIm values among them and W. coagulans LMG 6326^T and W. acidiproducens KCTC 13078^T were ranged from 76.61 to 79.59%. These 3 strains showed the digital DNA-DNA hybridization (dDDH) values of 20.7-23.6% when compared with W. coagulans LMG 6326^T and W. acidiproducens DSM 23148^T. The DNA G + C contents of strains PP-18^T, JC-4 and JC-7 were 45.82%, 45.86% and 45.86%, respectively. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphoglycolipids. The results of phenotypic and chemotaxonomic characteristics and whole-genome analysis indicated that the strains PP-18^T, JC-4 and JC-7 should be represented as a novel species within the genus Weizmannia for which the name Weizmannia acidilactici sp. nov. is proposed. The type strain is PP-18^T (=KCTC 33974^T = NBRC 113028^T = TISTR 2515^T).

Halobacillus fulvus sp. nov., a moderately halophilic bacterium isolated from shrimp paste (Ka-pi) in Thailand

An aerobic, Gram-stain-positive, endospore-forming, rod-shaped and moderately halophilic strain SKP4-6^T, was isolated from shrimp paste (Ka-pi) collected from Samut Sakhon Province, Thailand. Phylogenetic analysis revealed that strain SKP4-6^T belonged to the genus Halobacillus and was most closely related to Halobacillus salinus JCM 11546^T (98.6 %), Halobacillus locisalis KCTC 3788^T (98.6 %) and Halobacillus yeomjeoni KCTC 3957^T (98.6 %) based on 16S rRNA gene sequence similarity. The digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values between strain SKP4-6^T and its related species were 18.2-19.3 % and 69.84-84.51 %, respectively, which were lower than the threshold recommended for species delineation. The strain grew optimally at 30-40 °C, at pH 7.0 and with 10-15 % (w/v) NaCl. It contained l-Orn-d-Asp in the cell wall peptidoglycan. The DNA G+C content was 44.8 mol%. The major fatty acids were iso-C_15 : 0, anteiso-C_15 : 0 and anteiso-C_17 : 0. The predominant isoprenoid quinone was MK-7. Phosphatidylglycerol and diphosphatidylglycerol were present as major polar lipids. Based on this polyphasic approach, digital DNA-DNA relatedness and ANI values, strain SKP4-6^T represents a novel species of the genus Halobacillus, for which the name Halobacillus fulvus sp. nov. is proposed. The type strain is SKP4-6^T (=JCM 32624^T=TISTR 2595^T).

Mechanism of nitrite transporter NirC in motility, biofilm formation, and adhesion of avian pathogenic Escherichia coli

The Escherichia coli (E. coli) nirC gene encodes a nitrite transporter, which involved in transporting toxic nitrite (NO₂^-) from the environment into the bacteria. Although the deletion of nirC gene could cause changes in motility, adhesion in the previous study, and the virulence involved in the specified mechanism for pathogenic E. coli remains to be known. In the present work, we aimed to evaluate the role of NirC in a serotype O2:K1:H7 avian pathogenic Escherichia coli (APEC) strain. For this purpose, we generated a NirC-deficient mutant of APEC XM strain and examined its biological characteristics. The nirC gene deletion mutant enhanced ability of motility, decreased in biofilm formation, and it markedly reduced ability to adhere mouse brain microvascular endothelial cell b.End3 cells. For understanding its mechanism, sequentially we detected and found the stress regulator rpoS and its downstream genes csrA were up-regulated in NirC-deficient mutant while diguanylate cyclase gene dgcT was down-regulated. By high-performance liquid chromatography (HPLC) experiment, we demonstrated the concentration of intracellular 3',5'-cyclic diguanosine monophosphate (c-di-GMP) significantly decrease in nirC gene deletion mutant. Taken data together, we may make a conclusion with a possible signal pathway clue, due to NirC mutation, environmental NO₂^- accumulation leads to nitrite stress and inactivates c-di-GMP synthesis by stimulating the stress regulator RpoS, resulting in changes of biological characteristics.

Terrilactibacillus tamarindi sp. nov., isolated from bark of Tamarindus indica

A Gram-stain-positive, catalase-positive, facultatively anaerobic, terminal-spore-forming rod, designated strain BCM23-1^T, was isolated from bark of Tamarindus indica collected from Chiang Mai Province, Thailand. This strain produced d-lactic acid from glucose. It grew at 20-45 °C (optimum, 30 °C), pH 3.5-9 (optimum, pH 7.0) and in the presence of 1-4 % (w/v) NaCl. The cell-wall peptidoglycan contained meso-diaminopimelic acid (A1γ). The major isoprenoid quinone was menaquinone 7 (MK-7). Polar lipids analysis revealed the presence of diphosphatidylglycerol, phosphatidylglycerol, an unidentified aminophospholipid, an unidentified phospholipid and an unidentified lipid. The predominant cellular fatty acids were anteiso-C_17 : 0, anteiso-C_15:0, and iso-C_16 : 0 when cultivated on GYP agar plates. The 16S rRNA gene sequence similarity between strain BCM23-1^T and Terrilactibacillus laevilacticus NK26-11^T was 98.3 %. The draft genome of BCM23-1^T was 3.24 Mb in size and contained 3088 coding sequences with an in silico DNA G+C content of 37.1 mol%. The values of ANIb, ANIm and digital DNA-DNA hybridization between strain BCM23-1^T and T. laevilacticus NK26-11^T were 89.9, 90.8 and 40.4 %, respectively. The results of phenotypic and chemotaxonomic, 16S rRNA gene sequence similarity, and whole genome analyses support strain BCM23-1^T as representing a novel species of Terrilactibacillus for which the name Terrilactibacillus tamarindi sp. nov. is proposed. The type strain is BCM23-1^T (=LMG 31662^T=JCM 33748^T=TISTR 2841^T).

Lentibacillus lipolyticus sp. nov., a moderately halophilic bacterium isolated from shrimp paste (Ka-pi)

A Gram-stain-positive, aerobic, spore-forming, moderately halophilic bacterium, SSKP1-9^T, was isolated from traditional salted shrimp paste (Ka-pi) produced in Samut Sakhon Province, Thailand. This strain grew optimally at 37-40 °C, pH 7.0 and in the presence of 8-16 % (w/v) NaCl. The 16S rRNA gene sequence similarity values between strain SSKP1-9^T and Lentibacillus juripiscarius TISTR 1535^T and Lentibacillus halophilus TISTR 1549^T were 98.7 and 97.2 %, respectively. Based on 16S rRNA gene sequence similarity, strain SSKP1-9^T represents a distinct novel species, as shown by phenotypic traits, DNA-DNA hybridization and average nucleotide identity values. In addition, the whole-cell protein profile confirmed the novelty of the taxon. The genomic DNA G+C content was 44.6 mol%. The major isoprenoid quinone was MK-7. The cell-wall peptidoglycan contained meso-diaminopimelic acid. Polar lipid analysis revealed the presence of phosphatidylglycerol, diphosphatidylglycerol, four unidentified lipids, an unidentified phospholipid and an unidentified glycolipid. The major cellular fatty acids were anteiso-C_15 : 0, anteiso-C_17 : 0 and iso-C_16 : 0. The results of phenotypic and chemotaxonomic characteristics and whole-genome analysis support that strain SSKP1-9^T represents a novel species of Lentibacillus, for which the name Lentibacilluslipolyticus sp. nov. is proposed. The type strain is SSKP1-9^T (=JCM 32625^T=TISTR 2597^T).

Bacillus salacetis sp. nov., a slightly halophilic bacterium from Thai shrimp paste (Ka-pi)

A Gram-stain-positive, slightly halophilic, endospore-forming, strictly aerobic, rod-shaped bacterium, designated SKP7-4^T, was isolated from shrimp paste collected from Samut Sakhon province, Thailand. Strain SKP7-4^T grew at pH 6.0-9.0 (optimum, 7.5), at 20-40 °C (37 °C) and in 0-15 % (w/v) NaCl (1-3 %). The diamino acid found in the cell-wall peptidoglycan was meso-diaminopimelic acid. Menaquinone with seven isoprene units was the major isoprenoid quinone. Diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and three unidentified phospholipids were detected as polar lipids. It contained iso-C15 : 0 and anteiso-C15 : 0 as major cellular fatty acids. On the basis of 16S rRNA gene sequence analysis, strain SKP7-4^T belonged to the genus Bacillus and was closely related to Bacillus vietnamensis JCM 11124^T, Bacillus marisflavi JCM 11544^T, Bacillus aquimaris JCM 11545^T and Bacillusoryzaecorticis JCM 19602^T, with 98.7, 97.9, 97.8 and 97.8 % similarity, respectively. The draft genome of SKP7-4^T was 4.68 Mb with 5208 coding sequences with an average G+C content of 43.2 mol%. The ANIb and ANIm values of strain SKP7-4^T were 70.0 and 84.3 %, respectively, and the digital DNA-DNA hybridization value was 20 % in comparison with the draft genome of B. vietnamensis JCM 11124^T. On the basis of the results of phenotypic, chemotaxonomic and phylogenetic analyses, the strain should represent a novel species of the genus Bacillus and the name Bacillus salacetis sp. nov. is proposed. The type strain is SKP7-4^T (=JCM 33205^T=KCTC 43014^T=TISTR 2596^T).

Paenibacillus aurantiacus sp. nov., isolated from ant nest soil

A Gram-stain-positive, rod-shaped and endospore-forming bacterium, strain RC11T, isolated from ant nest soil collected from Udon Thani Province, Thailand was characterized in a taxonomic study based on a polyphasic approach. On the basis of 16S rRNA gene sequence analysis, strain RC11T was affiliated to the genus Paenibacillus and was closely related to Paenibacillus phyllosphaerae LMG 22192T with 98.1 % sequence similarity. Strain RC11T contained meso-diaminopimelic in the cell-wall peptidoglycan. The major menaquinone was MK-7. Anteiso-C15 : 0, iso-C16 : 0, anteiso-C17 : 0 and C16 : 0 were the predominant cellular fatty acids. Diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol were the major polar lipids. The DNA G+C content was 57.9 mol%. In addition, strain RC11T and P. phyllosphaerae LMG 22192T showed a low level of DNA-DNA relatedness (15.6-33.2 %). Therefore, strain RC11T represents a novel species of the genus Paenibacillus, for which the name Paenibacillus aurantiacus sp. nov. is proposed. The type strain is RC11T (=KCTC 33816T=LMG 29659T=TISTR 2452T).

Sporolactobacillus shoreicorticis sp.nov., a lactic acid-producing bacterium isolated from tree bark

A Gram-stain-positive, lactic acid-producing bacterium designed strain MK21-7T, was isolated from tree bark collected from the north east of Thailand. This strain was a facultatively anaerobic spore-forming rod that was catalase-negative. It contained meso-diaminopimelic acid in the cell wall peptidoglycan and had seven isoprene units (MK-7) as the predominant menaquinone. Major fatty acids of MK21-7T were anteiso-C17 : 0, iso-C16 : 0, anteiso-C15 : 0 and C18 : 1ω9c. Polar lipids were phosphatidglycerol, diphosphatidylglycerol, an unknown phospholipid, three unknown glycolipids and an unknown lipid. The results of 16S rRNA gene sequence analysis indicated that it represented a member of the genus Sporolactobacillus. MK21-7T showed the highest 16S rRNA gene sequence similarity to Sporolactobacillus terrae NBRC 101527T with 98.4 % similarity and exhibited 97.6 % similarity with Sporolactobacillus kofuensis NRIC 0334T, 97.5 % with Sporolactobacillus laevolacticus NRIC 0361T, 97.3 % with Sporolactobacillus nakayamaesubsp.nakayamae NRIC 0347T and 97.1 % with Sporolactobacillus nakayamaesubsp.racemicus NBRC 101524T. Analysis of the phylogenetic relationship based on 16S rRNA and gyrB gene sequencing revealed that the position of MK21-7T was clearly separated from all related species of the genus Sporolactobacillus. It had low DNA-DNA relatedness (22.8-57.2 %) with S. terrae NBRC 101527T and related type strains. The DNA G+C content was 43.1 mol%. On the basis of the results of the phenotypic, genotypic and chemotaxonomic studies, MK21-7T should be classified as representing a novel species of the genus Sporolactobacillus for which the name Sporolactobacillus shoreicorticis sp. nov. is proposed. The type strain is MK21-7T (=NBRC 111517T=LMG 29111T=TISTR 2466T).

Paenibacillus cathormii sp. nov., isolated from tree bark

A Gram-stain-positive, facultatively anaerobic, rod-shaped and endospore-forming bacterium, strain BK114-2^T isolated from tree bark in Thailand was characterized taxonomically using a polyphasic approach. Analysis based on comparison of 16S rRNA gene sequences indicated that strain BK114-2^T was affiliated to the genus Paenibacillus, and was closely related to Paenibacillus timonensis 2301032^T (96.7 % 16S rRNA gene sequence similarity), Paenibacillus phoenicis 3PO2SA^T (96.6 %) and Paenibacillus barengoltzii SAFN-016^T (96.4 %). Strain BK114-2^T contained meso-diaminopimelic acid in its cell-wall peptidoglycan. The polar lipids were composed of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, two unknown phospholipids, five unknown aminophospholipids and six unknown lipids. The only menaquinone detected was MK-7 and the dominant cellular fatty acids were C_16 : 0 (22.9 %), anteiso-C_15 : 0 (22.6 %), iso-C_16 : 0 (19.4 %) and anteiso-C_17 : 0 (14.7 %). The DNA G+C content was 52.0 mol%. Based on these results, strain BK114-2^T repreesents a novel species of the genus Paenibacillus, for which the name Paenibacillus cathormii sp. nov. is proposed. The type strain is BK114-2^T ( = KCTC 33251^T = TISTR 2282^T).

Paenibacillus quercus sp. nov., isolated from rhizosphere of Quercus aliena var. acuteserrata

A Gram-positive, spore-forming, rod-shaped and motile bacterium, designated strain 1-25(T), was isolated from the rhizosphere of Quercus aliena var. acuteserrata in Taibai Mountain, Shaanxi Province, China. 16S rRNA gene sequence analysis showed that strain 1-25(T) belongs to the genus Paenibacillus. Strain 1-25(T) was found to be closely related to Paenibacillus harenae and Paenibacillus castaneae with 96.0 and 95.9 % 16S rRNA gene sequence similarities, respectively. The strain was observed to grow optimally at 28 °C and pH 7.5. The major isoprenoid quinone was found to be menaquinone-7. The dominant cellular fatty acids were identified as anteiso-C15:0 and iso-C15:0. The diagnostic diamino acid in the cell-wall peptidoglycan was found to be meso-diaminopimelic acid. The DNA G+C content was determined to be 41.6 mol%. On the basis of phenotypic characteristics and molecular properties, strain 1-25(T) is considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillus quercus sp. nov. is proposed. The type strain is 1-25(T) (=CCTCC AB2013265(T) = KCTC 33194(T)).

Providencia thailandensis sp. nov., isolated from seafood processing wastewater

The bacterial strain C1112(T) was isolated from seafood processing wastewater collected from a treatment pond of the seafood factory in Songkhla Province, Thailand. Phylogenetic analysis based on concatenated sequences from the 16S rRNA gene and five housekeeping genes, fusA, lepA, leuS, gyrB and ileS respectively showed that the strain C1112(T) belonged to the genus Providencia, and share 91.75% similarity with P. stuartii DSM 4539(T). DNA-DNA hybridization between the strain C1112(T) and P. stuartii KCTC 2568(T) was 48.1% relatedness. Moreover, some results from biochemical properties indicated that the strain C1112(T) was distinguished from the phylogenetically closest relatives. The major fatty acids of the strain C1112(T) were C16:0, iso-C15:0, C14:0 and C17:0 cyclo and the DNA G+C content was 41 mol%. Based on the genotypic and phenotypic considerations, it should be classified as a novel species of the genus Providencia for which the name Providencia thailandensis sp. nov. is proposed. The type strain is C1112(T) (= KCTC 23281(T) =NBRC 106720(T)).

Isolation of Paenibacillus pinesoli sp. nov. from forest soil in Gyeonggi-Do, Korea

Using a new culture method for unculturable soil bacteria, strain NB5(T) was isolated from forest soil at Kyonggi University, and characterized taxonomically on the basis of 16S rRNA gene sequence as well as phenotypic and chemotaxonomic characteristics. The novel strain was a Gram- and catalase-positive, rod-shaped bacterium, which grew in the pH range 6.0-9.5 (optimum, 6.5-9.5) and at temperatures between 15°C and 45°C (optimum, 25-40°C). Growth was possible at 0-5% NaCl (optimum, 0% to 3%) in nutrient, Luria-Bertani, and trypticase soy broths (TSB), as well as R2A medium (with optimal growth in TSB). A phylogenetic analysis of the 16S rRNA gene sequence showed that the novel strain was affiliated with the genus Paenibacillus and had 96.8% and 96.5% similarity to P. nanensis MX2-3(T) and P. agaridevorans DSM 1355(T), respectively. The predominant menaquinone in NB5(T) was MK-7; the major fatty acids were anteiso-C15:0 and iso-C16:0; and the DNA G+C content was 54.5 mol%. We propose this strain as a novel species of the genus Paenibacillus, and suggest the name Paenibacillus pinesoli sp. nov. (type strain, KACC 17472(T)=KEMB 9005-025(T)=JCM 19203(T)).

Microbacterium neimengense sp. nov., isolated from the rhizosphere of maize

A Gram-positive, non-motile, non-spore-forming, rod-shaped bacterium, strain 7087T, was isolated from rhizosphere of maize in China. The strain grew at 4–50 °C and at pH 4–10, with optima of 37 °C and pH 7.0, respectively. Phylogenetic analysis based on the full-length 16S rRNA gene sequence revealed that strain 7087T was a member of the genus Microbacterium . High levels of 16S rRNA gene similarities were found between strain 7087T and Microbacterium binotii DSM 19164T (99.8 %). However, the DNA–DNA hybridization value between strain 7087T and Microbacterium binotii DSM 19164T was 24.2 %. The DNA G+C content of strain 7087T was 69.9 mol%. The major fatty acids were anteiso-C17 : 0 (36.45 %), anteiso-C15 : 0 (36.08 %) and iso-C16 : 0 (16.11 %). The predominant menaquinones were MK-10 (28.1 %), MK-11 (54.8 %) and MK-12 (17.1 %). The diagnostic diamino acid in the cell-wall peptidoglycan was ornithine. The major polar lipids are diphosphatidylglycerol, unknown phospholipids, an unknown glycolipid and unknown amino lipids. On the basis of these results, strain 7087T is considered to represent a novel species of the genus Microbacterium , for which the name Microbacterium neimengense sp. nov. is proposed. The type strain is 7087T ( = ACCC 03008T = DSM 24985T).

Paenibacillus beijingensis sp. nov., a novel nitrogen-fixing species isolated from jujube garden soil

A novel Gram-positive, rod-shaped, motile, spore-forming, nitrogen-fixing bacterium, designated strain 7188(T), was isolated from jujube rhizosphere soil in Beijing, China. The strain grew at 4-40 °C and pH 6-12, with an optimum of 30 °C and pH 7.0, respectively. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that strain 7188(T) is a member of the genus Paenibacillus. Levels of 16S rRNA gene sequence similarities between strain 7188(T) and the type strains of all recognized members of the genus Paenibacillus were below 96 %. The major cellular fatty acids were anteiso-C(15:0), anteiso-C(17:0) and C(16:0). The predominant menaquinone was MK-7. The DNA G+C content of strain 7188(T) was 60.3 mol%. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and unknown aminophospholipids. The diamino acid in the cell wall peptidoglycan is meso-diaminopimelic acid. On the basis of these results, strain 7188(T) is considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillus beijingensis sp. nov. is proposed. The type strain is 7188(T) (=ACCC 03082(T) = DSM 24997(T)).

Heterotrophic nitrification by Achromobacter xylosoxidans S18 isolated from a small-scale slaughterhouse wastewater

Heterotrophic carbon utilizing microbes were acclimatized in the laboratory by inoculating sludge collected from the waste discharge pond of a small-scale rural abattoir in India in a nutrient solution intermittently fed with glucose and ammonium chloride. Cultures of 10 well-developed isolates were selected and grown in a basal medium containing glucose and ammonium chloride. Culture supernatants were periodically analyzed for ammonium nitrogen (NH(4)(+)-N) and chemical oxygen demand (COD). Polyphasic taxonomic study of the most active nitrifier (S18) was done. Half saturation concentration (K(s)), maximum rate of substrate utilization (k), yield coefficient (Y) and decay coefficient (K(d)) were determined from the Lineweaver-Burk plot using the modified Monod equation. S18 was able to remove 97 ± 2% of (NH(4)(+)-N) and 88 ± 3% of COD. Molecular phylogenetic study supported by physiological and biochemical characteristics assigned S18 as Achromobacter xylosoxidans. Nitrification activity of A. xylosoxidans was demonstrated for the first time, while interestingly, the distinctive anaerobic denitrification property was preserved in S18. K (s) values were determined as 232.13 ± 1.5 mg/l for COD reduction and 2.131 ± 1.9 mg/l for NH(4)(+)-N utilization. Yield coefficients obtained were 0.4423 ± 0.1134 mg of MLVSS/mg of COD and 0.2461 ± 0.0793 mg of MLVSS/mg of NH(4)(+)-N while the decay coefficients were 0.0627 ± 0.0013 per day and 0.0514 ± 0.0008 per day, respectively. After a contact period of 24 h, 650 ± 5 mg/l solids were produced when the initial concentration of COD and NH(4)(+)-N were 1820 ± 10 mg/l and 120 ± 5.5 mg/l, respectively. This is the first report on the kinetic coefficients for carbon oxidation and nitrification by a single bacterium isolated from slaughterhouse wastewater.

Salinisphaera orenii sp. nov., isolated from a solar saltern

A taxonomic study was performed on two isolates, designated strains MK-B5(T) and MK-B7, isolated from sediment of a solar saltern pond in Gomso Bay, Republic of Korea. Comparative 16S rRNA gene sequence analysis showed that strains MK-B5(T) and MK-B7 belong to the Gammaproteobacteria and are related most closely to Salinisphaera shabanensis JCM 11575(T) ( = E1L3A(T)) (96.3 and 96.5% similarity, respectively), Salinisphaera dokdonensis KCCM 90064(T) ( = CL-ES53(T)) (95.6 and 95.6%) and Salinisphaera hydrothermalis JCM 115514(T) ( = EPR70(T)) (95.1 and 95.3%). The level of 16S rRNA gene sequence similarity between strains MK-B5(T) and MK-B7 was 99.8%. The G+C contents of their genomic DNAs were 63.4 and 63.6 mol%, respectively, and the major respiratory quinone was ubiquinone-8. DNA-DNA relatedness between strains MK-B5(T) and MK-B7 was 98%, indicating that the two isolates represent a single species. However, the level of DNA-DNA relatedness between the two isolates and S. shabanensis E1L3A(T) (26.4-30.8%) indicates that they represent a novel species. Strains MK-B5(T) and MK-B7 possessed C(14:0), C(16:0) and C(19:0)ω8c cyclo as major fatty acids. The two isolates were Gram-stain-negative, strictly aerobic, short rod-shaped and motile. They grew at 10-40 °C (optimum, 35-37 °C), at pH 5.0-8.5 (optimum, 7.0-7.5) and with 5-25% (w/v) NaCl (optimum, 15% NaCl). On the basis of phenotypic and phylogenetic analyses, strains MK-B5(T) and MK-B7 are thus considered to represent a novel species of the genus Salinisphaera, for which the name Salinisphaera orenii sp. nov. is proposed. The type strain is MK-B5(T) ( = KCTC 23198(T) = JCM 17073(T)).

Gluconobacter nephelii sp. nov., an acetic acid bacterium in the class Alphaproteobacteria

Three strains, RBY-1T, PHD-1 and PHD-2, were isolated from fruits in Thailand. The strains were Gram-negative, aerobic rods with polar flagella, produced acetic acid from ethanol and did not oxidize acetate or lactate. In phylogenetic trees based on 16S rRNA gene sequences and 16S–23S rRNA gene internal transcribed spacer (ITS) sequences, the strains formed a cluster separate from the type strains of recognized species of the genus Gluconobacter. The calculated 16S rRNA gene sequence and 16S–23S rRNA gene ITS sequence similarities were respectively 97.7–99.7 % and 77.3–98.1 %. DNA G+C contents ranged from 57.2 to 57.6 mol%. The strains showed high DNA–DNA relatedness of 100 % to one another, but low DNA–DNA relatedness of 11–34 % to the tested type strains of recognized Gluconobacter species. Q-10 was the major quinone. On the basis of the genotypic and phenotypic data obtained, the three strains clearly represent a novel species, for which the name Gluconobacter nephelii sp. nov. is proposed. The type strain is RBY-1T ( = BCC 36733T = NBRC 106061T = PCU 318T), whose DNA G+C content is 57.2 mol%.

Identification of moderately halophilic bacteria from Thai fermented fish ( pla-ra ) and proposal of Virgibacillus siamensis sp. nov

Forty-one isolates of moderately halophilic bacteria were isolated from fermented fish (pla-ra) in Thailand. On the basis of their phenotypic and chemotaxonomic characteristics, DNA-DNA relatedness and 16S rRNA gene sequences analyses, they were divided into six groups. The isolates in Group I to V were Gram-positive rod-shaped bacteria. They contained meso-diaminopimelic acid in the cell-wall peptidoglycan and menaquinone with seven isoprene units (MK-7). An isolate in Group VI was a Gram-negative rod-shaped bacterium. The DNA G+C contents of tested strains ranged from 36.5-63 mol%. Ten strains (Group I) were identified as Virgibacillus dokdonensis, 13 isolates (Group II) as V. halodenitrificans, 14 isolates (Group III) as V. marismortui, 1 isolate (Group IV) as Virgibacillus sp., 2 isolates (Group V) as Bacillus vietnamnensis, and 1 isolate (Group VI) as Chromohalobacter salexigens. Isolate MS3-4 in Group IV was closely related to V. carmonensis KCTC 3819(T) (95.9%). This strain contained anteiso-C(15:0) (55.8%) and anteiso-C(17:0) (17.7%) as major cellular fatty acids and had phosphatidylglycerol, diphosphatidylglycerol and an unidentified glycolipid as polar lipids. The DNA G+C content of MS3-4 was 38.0 mol%. The strain from Group IV is proposed as Virgibacillus siamensis sp. nov. and MS3-4(T) is the type strain (JCM 15395(T) =PCU 312(T) =TISTR 1957(T)).

Cohnella xylanilytica sp. nov. and Cohnella terrae sp. nov., xylanolytic bacteria from soil

Two xylan-degrading bacteria, strains MX15-2T and MX21-2T, were isolated from soils collected in Nan province, Thailand. Cells were Gram-reaction-positive, facultatively anaerobic, spore-forming and rod-shaped. They contained meso-diaminopimelic acid in the cell-wall peptidoglycan. The major menaquinone was MK-7. iso-C16 : 0 and anteiso-C15 : 0 were the predominant cellular fatty acids. Diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and lysyl-phosphatidylglycerol were the major polar lipids. The genomic DNA G+C contents of strains MX15-2T and MX21-2T were 63.0 and 65.1 mol%, respectively. Phylogenetic analysis using 16S rRNA gene sequences showed that strains MX15-2T and MX21-2T were affiliated with the genus Cohnella and were closely related to Cohnella thermotolerans CCUG 47242T, with 96.5 and 95.6 % sequence similarity, respectively. The strains could be clearly distinguished from each other and from all known species of the genus Cohnella based on their physiological and biochemical characteristics as well as their phylogenetic positions and levels of DNA–DNA hybridization. Therefore, these two strains represent novel species of the genus Cohnella, for which the names Cohnella xylanilytica sp. nov. (type strain MX15-2T =KCTC 22294T =PCU 309T =TISTR 1891T) and Cohnella terrae sp. nov. (type strain MX21-2T =KCTC 22295T =PCU 310T =TISTR 1892T) are proposed.

Gracilibacillus thailandensis sp. nov., from fermented fish (pla-ra)

A novel strain, designated TP2-8(T), was isolated from fermented fish (pla-ra) in Thailand. It stained Gram-positive and the cells were aerobic, endospore-forming rods. The strain grew at pH 6-8 (optimum pH 7), 15-55 degrees C (optimum 37 degrees C) and 1-22 % (w/v) NaCl (optimum 5-10 %). It contained meso-diaminopimelic in the cell-wall peptidoglycan. MK-7 and cellular fatty acids anteiso-C(15 : 0), iso-C(15 : 0) and anteiso-C(17 : 0) were major components. Polar lipids diphosphatidylglycerol and phosphatidylglycerol and unidentified lipids were detected. The DNA G+C content was 37.6 mol%. Comparison of the 16S rRNA gene sequence of strain TP2-8(T) with those of other members of the family Bacillaceae indicated that it was a member of the genus Gracilibacillus (94.9-99.2 % sequence similarity) and was closely related to Gracilibacillus saliphilus YIM 91119(T) (99.2 % similarity), G. lacisalsi BH312(T) (98.6 %), G. orientalis XH-63(T) (97.7 %), 'G. quinghaiensis' YIM C229 (97.7 %) and G. boraciitolerans T-16X(T) (97.2 %). Strain TP2-8(T) showed low DNA-DNA relatedness (< or = 49%) to G. saliphilus YIM 91119(T), G. lacisalsi DSM 19029(T), G. orientalis CCM 7326(T), 'G. quinghaiensis' DSM 17858 and G. boraciitolerans JCM 21714(T). On the basis of the physiological and biochemical characteristics and molecular data presented, strain TP2-8(T) is proposed to represent a novel species, Gracilibacillus thailandensis sp. nov. (type strain TP2-8(T) =JCM 15569(T) =PCU 304(T) =TISTR 1881(T)).

Oceanobacillus kapialis sp. nov., from fermented shrimp paste in Thailand

A Gram-positive, rod-shaped, strictly aerobic, spore-forming, moderately halophilic bacterium, designated strain SSK2-2T, was isolated from fermented shrimp paste (ka-pi) produced in Thailand. It contained MK-7 as the predominant menaquinone and meso-diaminopimelic acid in the cell-wall peptidoglycan. The isolate grew at 8-43 degrees C, pH 6-9 and in 0.5-24% (w/v) NaCl (optimum, 6-14% NaCl). The major cellular fatty acids were anteiso-C15:0 and anteiso-C17:0. Phosphatidylglycerol and diphosphatidylglycerol were the major polar lipid components. The DNA G+C content was 39.7 mol%. Comparative 16S rRNA gene sequence analyses showed that strain SSK2-2T was most closely related to Oceanobacillus picturae KCTC 3821T with 98.7% sequence similarity. Based on phenotypic and molecular features combined with DNA-DNA hybridization results (<or=24.9% with O. picturae KCTC 3821T), this strain represents a novel species of the genus Oceanobacillus for which the name Oceanobacillus kapialis sp. nov. is proposed; the type strain is SSK2-2T (=KCTC 13177T=PCU 300T=TISTR 1858T).

Salinivibrio siamensis sp. nov., from fermented fish (pla-ra) in Thailand

A Gram-negative, facultatively anaerobic, moderately halophilic bacterium, strain ND1-1(T), was isolated from fermented fish (pla-ra) in Thailand. The cells were curved rods, motile and non-endospore-forming. The novel strain grew optimally at 37 degrees C, at pH 8 and in the presence of 9-10 % (w/v) NaCl. The predominant respiratory lipoquinone was Q-8. The major cellular fatty acids were C(16 : 0) and C(12 : 0). Polar lipid analysis revealed the presence of phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. The DNA G+C content was 49.0 mol%. Comparative 16S rRNA gene sequence analyses indicated that strain ND1-1(T) was closely related to Salinivibrio costicola, which comprises three subspecies, and Salinivibrio proteolyticus with gene sequence similarities of 98.3-98.6 %. Strain ND1-1(T) showed low levels of DNA-DNA relatedness with S. costicola subsp. costicola JCM 15095(T) (33.2 %), S. costicola subsp. alcaliphilus DSM 16359(T) (38.4 %), S. costicola subsp. vallismortis JCM 15096(T) (59.7 %), and S. proteolyticus AF-2004(T) (42.1 %). On the basis of the physiological and biochemical characteristics and the molecular data presented, strain ND1-1(T) should be classified as a novel species of the genus Salinivibrio for which the name Salinivibrio siamensis sp. nov. is proposed. The type strain is ND1-1(T) (=JCM 14472(T)=PCU 301(T)=TISTR 1810(T)).

Salinicoccus siamensis sp. nov., isolated from fermented shrimp paste in Thailand

Fifteen strains of moderately halophilic, Gram-positive cocci were isolated from a traditional fermented shrimp paste ('ka-pi') produced in Thailand. These bacteria were strictly aerobic, non-motile, non-sporulating and catalase- and oxidase-positive. They produced orange pigment and grew in the presence of 1.5-25 % (w/v) NaCl. They grew optimally in 10 % (w/v) NaCl, at pH 8.5 and at 37 degrees C. The cell-wall peptidoglycan was of l-Lys type. Menaquinone with six isoprene units (MK-6) was a major component. The dominant cellular fatty acids were anteiso-C(15 : 0) and iso-C(15 : 0). DNA G+C contents were in the range 44.5-47.5 mol%. Comparative 16S rRNA gene sequence analyses indicated that representative strain PN1-2(T) was related most closely to Salinicoccus roseus JCM 14630(T), with 97.3 % similarity. The other novel strains were included in the same species based on their levels of DNA-DNA relatedness to strain PN1-2(T) (> or =76.6 %) but showed low DNA-DNA relatedness to S. roseus JCM 14630(T) (21.7 %). On the basis of the phenotypic and molecular data presented, the 15 novel strains are suggested to represent a single novel species of the genus Salinicoccus, for which the name Salinicoccus siamensis sp. nov. is proposed. The type strain is PN1-2(T) (=JCM 12822(T) =PCU 242(T) =TISTR 1562(T)).

Chromobacterium subtsugae sp. nov., a betaproteobacterium toxic to Colorado potato beetle and other insect pests

Strain PRAA4-1(T), a motile, Gram-negative, violet-pigmented bacterium, was isolated from Maryland forest soil and found to be orally toxic to Colorado potato beetle larvae and other insects. Morphological, biological, biochemical and molecular characterization revealed that this strain was most similar to Chromobacterium violaceum, the type species and only currently recognized member of the genus Chromobacterium. DNA-DNA hybridization with C. violaceum ATCC 12472(T) was 27 %. Phylogenetic analysis of 16S rRNA gene sequences revealed that strain PRAA4-1(T) and Chromobacterium violaceum form a monophyletic clade, with the closest ancestral taxon Vogesella indigofera within the Betaproteobacteria. On the basis of phenotypic, genotypic and phylogenetic analyses, strain PRAA4-1(T) (=NRRL B-30655(T)=DSM 17043(T)) is proposed as the type strain of a novel species of the genus Chromobacterium, Chromobacterium subtsugae sp. nov.

Piscibacillus salipiscarius gen. nov., sp. nov., a moderately halophilic bacterium from fermented fish (pla-ra) in Thailand

A Gram-positive, spore-forming and moderately halophilic bacterium was isolated from fermented fish (pla-ra) in Thailand. Cells of the isolate, RBU1-1T, were strictly aerobic, motile rods and contained meso-diaminopimelic acid in the cell-wall peptidoglycan. Menaquinone with seven isoprene units (MK-7) was the predominant quinone. This isolate grew at 15–48 °C, pH 5–9 and in 2–30 % NaCl (optimally 10–20 %). The major cellular fatty acids were iso-C15 : 0 and anteiso-C15 : 0. Polar lipid analysis revealed the presence of phosphatidylglycerol and diphosphatidylglycerol. The DNA G+C content was 36.7 mol%. 16S rRNA gene sequence analysis revealed that strain RBU1-1T was a member of the family Bacillaceae, and belonged to a cluster with Filobacillus and Tenuibacillus; strain RBU1-1T showed 16S rRNA gene sequence similarities of 96.0–96.9 % to members of these two genera. Strain RBU1-1T could also be differentiated from members of the genera Filobacillus and Tenuibacillus based on certain phenotypic characteristics such as cell-wall composition, mode of flagellation and growth pH range. Therefore, strain RBU1-1T is considered to represent a novel species in a new genus in the family Bacillaceae, for which the name Piscibacillus salipiscarius gen. nov., sp. nov. is proposed. The type strain of Piscibacillus salipiscarius is RBU1-1T (=JCM 13188T=PCU 270T=TISTR 1571T).

Lentibacillus kapialis sp. nov., from fermented shrimp paste in Thailand

Two strains of strictly aerobic, moderately halophilic Gram-positive rods were isolated from fermented shrimp paste (‘ka-pi’) produced in Thailand. They produced a red pigment and grew optimally in the presence of 5–30 % NaCl. The diagnostic diamino acid in the cell-wall peptidoglycan was meso-diaminopimelic acid. The predominant menaquinone was MK-7. The major cellular fatty acid was anteiso-C15 : 0. Phosphatidylglycerol, diphosphatidylglycerol and two unidentified glycolipids were found to be the major polar lipid components. The DNA G+C content was 41.2–41.6 mol%. Comparative 16S rRNA gene sequence analyses showed that strain PN7-6T was most closely related to Lentibacillus salarius KCTC 3911T with 96.5 % sequence similarity. On the basis of phenotypic and molecular properties, the two isolates represent a novel species of the genus Lentibacillus, for which the name Lentibacillus kapialis sp. nov. is proposed. The type strain is PN7-6T (=JCM 12580T=PCU 259T=TISTR 1551T).

Lentibacillus halophilus sp. nov., from fish sauce in Thailand

Fifteen strains of extremely halophilic bacteria were isolated from fish sauce (nam-pla) collected in Thailand at various stages of the fish-fermentation process. The isolates were strictly aerobic, spore-forming, Gram-positive rods. They grew optimally in the presence of 20–26 % NaCl. The cell-wall peptidoglycan contained meso-diaminopimelic acid. The predominant menaquinone was MK-7. The major cellular fatty acids were anteiso-C15 : 0 and anteiso-C17 : 0. Polar lipid analysis revealed the presence of phosphatidylglycerol, diphosphatidylglycerol and two unidentified glycolipids. The DNA G+C content was 42.1–43.1 mol%. On the basis of the 16S rRNA gene sequence, a representative strain, PS11-2T, was found to be closely related to Lentibacillus juripiscarius JCM 12147T (97.3 % similarity). The 15 strains were included in the same species on the basis that the levels of DNA–DNA relatedness with strain PS11-2T were greater than 70 %. They could be distinguished from L. juripiscarius and other Lentibacillus species on the basis of several phenotypic characteristics and low levels of DNA–DNA relatedness (⩽19.4 %). Therefore, the strains represent a novel species of the genus Lentibacillus, for which the name Lentibacillus halophilus sp. nov. is proposed. The type strain is PS11-2T (=JCM 12149T=TISTR 1549T=PCU 240T).

FimX, a multidomain protein connecting environmental signals to twitching motility in Pseudomonas aeruginosa

Twitching motility is a form of surface translocation mediated by the extension, tethering, and retraction of type IV pili. Three independent Tn5-B21 mutations of Pseudomonas aeruginosa with reduced twitching motility were identified in a new locus which encodes a predicted protein of unknown function annotated PA4959 in the P. aeruginosa genome sequence. Complementation of these mutants with the wild-type PA4959 gene, which we designated fimX, restored normal twitching motility. fimX mutants were found to express normal levels of pilin and remained sensitive to pilus-specific bacteriophages, but they exhibited very low levels of surface pili, suggesting that normal pilus function was impaired. The fimX gene product has a molecular weight of 76,000 and contains four predicted domains that are commonly found in signal transduction proteins: a putative response regulator (CheY-like) domain, a PAS-PAC domain (commonly involved in environmental sensing), and DUF1 (or GGDEF) and DUF2 (or EAL) domains, which are thought to be involved in cyclic di-GMP metabolism. Red fluorescent protein fusion experiments showed that FimX is located at one pole of the cell via sequences adjacent to its CheY-like domain. Twitching motility in fimX mutants was found to respond relatively normally to a range of environmental factors but could not be stimulated by tryptone and mucin. These data suggest that fimX is involved in the regulation of twitching motility in response to environmental cues.

A simple, rapid method for demonstrating bacterial flagella

We developed a simple, rapid method for demonstrating flagellation of bacteria using the fluorescent protein stain NanoOrange (Molecular Probes, Eugene, Oreg.). The NanoOrange reagent binds to hydrophobic regions of proteins, which results in substantial enhancement of fluorescence. Unbound reagent is essentially nonfluorescent. NanoOrange fluorescently stained bacterial cell bodies, as well as flagella and other appendages, which could be directly observed by epifluorescence microscopy. Detection of flagella was further improved by using a charge-coupled device camera for image capture and processing. The reliability of the method was tested by using 37 pure cultures of marine bacteria. Detection of flagella on the isolates by NanoOrange staining was compared to detection by transmission electron microscopy (TEM). For 36 of 37 cultures, the two methods yielded the same results. In one case, flagella were detected by TEM but not by NanoOrange, although the difference may be attributable to differences between the culture preparations. NanoOrange staining is rapid (10 to 15 min) and does not require fixation or dehydration, so live samples can be stained. Since NanoOrange is a general protein stain and works directly in seawater, it may also prove to be useful for staining other proteinaceous material that is of interest to aquatic microbial ecologists.

Generation and characterization of murine antiflagellum monoclonal antibodies that are protective against lethal challenge with Pseudomonas aeruginosa

Two murine monoclonal antibodies, IIG5 (IgG3) and IVE8 (IgG2a), that bind to Pseudomonas aeruginosa type a flagella and type b flagella, respectively, were prepared by conventional hybridoma methodology. Specificity of each monoclonal antibody for type a or type b flagella was demonstrated by enzyme-linked immunosorbent assay, indirect immunofluorescence, and immunoblotting. The percentage of P. aeruginosa isolates recognized by each monoclonal antibody was analyzed by enzyme-linked immunosorbent assay. Among a panel of 257 flagellated P. aeruginosa clinical isolates, IIG5 bound to 67.7% of the isolates and IVE8 bound to another 30.7%, for a combined coverage of 98.4%. Inhibition of motility of P. aeruginosa by the monoclonal antibodies was observed in vitro in a soft agar assay and was dose dependent. The protective efficacy of IIG5 and IVE8 was examined in a mouse burn wound sepsis model. The antiflagellum monoclonal antibodies provided specific and significant prophylactic and therapeutic protection against lethal challenge with P. aeruginosa strains.

In situ identification of bacterial species in marine microfouling films by using an immunofluorescence technique

An immunofluorescence technique was developed for the in situ identification of specific bacteria in marine microfouling films. Microorganisms adherent to glass plates after 30 days of immersion in a synthetic seawater system were cultured and classified by biochemical tests, flagellar arrangement, and the API 20E system. All isolates were gram-negative aerobic or facultative motile rods, predominantly Pseudomonas spp. Rabbit antisera to the five dominant organisms including Achromobacter spp., Comamonas terrigena, P. putrefaciens, a yellow-pigmented Pseudomonas sp., and Vibrio alginolyticus were prepared. These antisera were shown to be species specific in indirect immunofluorescence assays against a battery of 26 marine isolates from 14 bacterial species, with the exception of antisera to the Pseudomonas spp, which cross-reacted with each other but not with test bacteria of other genera. These immunofluorescent reagents enabled the in situ identification of all five bacterial species in microfouling films. Low-surface-energy test plates had smaller numbers of adherent bacteria in microfouling films than medium-surface-energy test plates, suggesting that the degree of microfouling may be influenced by the surface energy. In addition, the reagents could identify up to 39% of the attached bacteria in microfouling films spontaneously formed on steel plates in flow cells deployed in different areas of the Atlantic Ocean. The microbial composition of the ocean-formed films varied with the geographical area of their formation. The present results indicate that immunofluorescence techniques may provide a rapid and reliable means to identify, in situ, specific bacteria in marine microfouling films.

Differentiation of Alcaligenes-like bacteria of avian origin and comparison with Alcaligenes spp. reference strains

Although standard biochemical tests used for the identification of Alcaligenes spp. revealed only minor differences, the oxidative low-peptone technique clearly differentiated between Alcaligenes-like bacteria of avian origin and Alcaligenes spp. reference strains. Based on their colonial morphology, biochemical profiles, and hemagglutination, the Alcaligenes-like bacteria of avian origin were further divided into two subgroups, C1-T1 and C2-T2. Colonies of subgroup C1-T1 were nondescript, round, raised, glistening, translucent, greyish, and about 2 mm in diameter. Colonies of subgroup C2-T2 were off-white, flat, dry and wrinkled, generally round, and resembled tiny lily pads. Biochemical profiles by the oxidative low-peptone method showed the C1-T1 subgroup alkalinizing only three substrates (citrate, acetate, and succinate), whereas the C2-T2 subgroup alkalinized eight substrates (citrate, acetate, butyrate, itaconate, malonate, saccharate, succinate, and M-tartrate). Subgroup C1-T1 agglutinated human, chicken, and turkey erythrocytes, whereas subgroup C2-T2 did not. The recognition of these two subgroups within the Alcaligenes-like bacteria of avian origin is important, since it may explain the differences seen in pathogenicity among isolates.