Microorganisms associated with Maari, a Baobab seed fermented product

Plant-Based Alkaline Fermented Foods as Sustainable Sources of Nutrients and Health-Promoting Bioactive Compounds

Traditional food fermentation is a practice that precedes human history. Acidic products such as yogurts and sourdoughs or alcoholic beverages produced through lactic acid or yeast fermentations, respectively, are widely described and documented. However, a relatively less popular group of fermented products known as alkaline fermented foods are common traditional products in Africa and Asia. These products are so called “alkaline” because the pH tends to increase during fermentation due to the formation of ammonia resulting from protein degradation by Bacillus species. Plant-based alkaline fermented foods (AFFs) are generally produced from legumes including soybean, non-soybean leguminous seeds, and other non-legume plant raw materials. Alkaline fermented food products such as natto, douchi, kinema, doenjang, chongkukjang, thua nao, meitauza, yandou, dawadawa/iru, ugba, kawal, okpehe, otiru, oso, ogiri, bikalga, maari/tayohounta, ntoba mbodi, cabuk, and owoh are produced at small industrial scale or household levels and widely consumed in Asia and Africa where they provide essential nutrients and health-promoting bioactive compounds for the population. Alkaline food fermentation is important for sustainable food security as it contributes to traditional dietary diversity, significantly reduces antinutritional components in raw plant materials thereby improving digestibility, improves health via the production of vitamins, and may confer probiotic and post-biotic effects onto consumers. In this review, we present currently available scientific information on plant-based AFFs and their role as sustainable sources of nutrients and bioactive compounds for improved health. Finally, we provide perspectives on research needs required to harness the full potential of AFFs in contributing to nutrition and health.

Metabarcoding analysis and fermentation performance of the dominant fungal microbiota associated with the Algerian traditional date product "Btana"

The study highlights the fungal diversity of the traditional Algerian date's product "Btana" prepared with direct Btana method (DBM) and undirect Btana method (UBM). Btana fungal populations were analyzed through 28S metabarcoding. Data treatment resulted in 122,997 reads representing three Phyla in which 76% reads (46 OTUs) belong to Ascomycota phylum. Zygosaccharomyces rouxii was the most prevailed species accounting for 35.40% of the total population. Similarity percentage analysis revealed a low level of resemblance in species in each of the two Btana types (DBM: 17.26%, UBM: 16.87). According to HPLC analysis, lactate was detected in nine samples within a range of 0.87-23.06 g/100g. Culture plating and subsequent D1/D2 domain of 28s DNA analysis showed the prevalence of Z. rouxii. Fermentation of non-renewed date medium revealed a high ethanol production (21.31 ± 2.89 g/100g) by Lachancea thermotolerans and 5.87 g/100g of lactates by Kluyveromyces delphensis. Enzymatic assay revealed a high esterase (C4) and naphtol-AS-BI-phosphohydrolase activity by L. thermotolerans, K. delphensis, and Pichia subpelliculosa, while a high level of α-fucosidase was recorded for L. thermotolerans and P. subpelliculosa. The current results demonstrated that the traditional date product Btana is a promising source for yeasts useful in production of value-added products like bioethanol and lactic acid using low-income date cultivars.

Technological Applications of Macrococcus caseolyticus and its Impact on Food Safety

Macrococcus spp. are Gram-positive cocci that belong to the Staphylococcaceae family; they are closely related to staphylococci, but, unlike staphylococci, they are not considered as human pathogens. Macrococcus spp. are recognized as relevant veterinary pathogens, and their presence has been reported in food products of animal origin. Macrococcus caseolyticus, the most studied species of the Macrococcus genus, is associated with the development of aroma and flavor in fermented foods and is, thus, used as starter cultures in fermentations. However, certain important issues regarding food safety must be taken into account when employing these microorganisms in fermentations. Recent studies have reported the presence of genes associated with resistance to methicillin and other antibiotics in M. caseolyticus. This can be harmful to human health as these genes can be transferred to other bacteria present in the food, mainly staphylococcal species. This work, therefore, aims to highlight the importance of a more critical view on the presence of macrococci in foods and the possible indirect risks to human health.

Technologically relevant Bacillus species and microbial safety of West African traditional alkaline fermented seed condiments

Fermented food condiments serve as a major source of nutrients to many homes in West Africa, especially among the rural poor who use these condiments as a cheap source of protein substitute for milk and other animal protein sources. Traditional fermented West African condiments are produced by spontaneous fermentation of legumes and protein-rich seeds of both cultivated and wild plant species. These fermented condiments are culturally accepted and widely produced in the West African sub-region, and rely on indigenous microbiota responsible for taste, texture, aroma development and the overall unique product characteristics. Detailed understanding of fermentation microbiota and their unique technological and functional properties are fundamental in developing products with enhanced quality and safety, as well as development of specific locally adapted starter cultures. Technologically relevant Bacillus spp., mainly Bacillus subtilis, are the predominant fermentative bacteria responsible for the natural fermentation of condiments across West Africa. Other species of Bacillus including B. amyloliquefaciens, B. licheniformis, B. pumilus, B. megaterium, B. sphaericus, B. cereus, B. badius and B. fusiformis are also frequently involved in the fermentation process. These bacterial species are responsible for flavor development, bio-conversion of complex food molecules, and production of antimicrobial compounds that impact shelf-life and safety, and in some instances, may confer host-beneficial health effects beyond basic nutrition. First, this review provides currently available information on the technologically relevant Bacillus species isolated from fermented food condiments in nine (9) West African countries. In addition, perspectives on harnessing the potentials of the technologically beneficial bacterial strains in fermented condiments in West Africa for enhanced food safety, quality and overall food security is presented.

Trends in the application of Bacillus in fermented foods

Bacillus species such as Bacillus subtilis and Bacillus amyloliquefaciens are widely used to produce fermented foods from soybeans and locust beans in Asian and West African countries, respectively. Genomic information for B. subtilis strains isolated from Asian Bacillus-fermented foods (BFFs) has been gathered, and the chemical components of fermented products were defined with metabolomic approaches, facilitating the development of new starter strains and the evaluation of health claims. On the other hand, although advanced studies have been performed for some commercially produced BFFs, home-manufactured products still remain to be characterized in rural areas. In West Africa, the microbial flora of BFFs was examined in detail, leading to the isolation of candidates of the starter that produced bacteriocin against Bacillus cereus contaminating the products. These studies may provide a choice of Bacillus strains in food application and increase opportunities for further usage of Bacillus in foods.

Physicochemical, nutritional, functional, rheological, and microbiological properties of sorghum flour fermented with baobab fruit pulp flour as starter

Two sorghum genotypes termed Wad-Ahmed (high tannin) and Tabat (low tannin) in Sudan were fermented with different starter levels (0%, 25%, 50%, 75%, and 100%) of fermented baobab fruit pulp flour (FBFPF). Chemical composition, antinutrients, extracted minerals, and the microbiological, physicochemical, functional, rheological, and pasting properties from the fermented flours were determined. Fermentation of both genotypes with higher levels of FBFPF starter enhanced protein, fiber, ash, and major mineral contents and extractability (p ≤ 0.05). Total acidity, bulk density, rheological properties, in vitro protein, and starch digestibility of both genotypes increased with FBFPF levels, with a concomitant decrease in pH, phytate and tannin contents, and water and fat absorption capacities (p ≤ 0.05). Microbial loads, especially lactic acid bacteria, increased with increasing FBFPF starter levels in both genotypes. Use of FBFPF as a starter in the fermentation of sorghum flour can improve the nutritional value of sorghum. This could be usefully applied to the food industry for the development of fermented sorghum products.

Globicatella sanguinis Osteomyelitis and Bacteremia: Review of an Emerging Human Pathogen with an Expanding Spectrum of Disease

Background

Globicatella sanguinis is an uncommon pathogen that may be misdiagnosed as viridans group streptococci. We review the literature of Globicatella and report 2 clinical cases in which catalase-negative Gram-positive cocci resembling viridans group streptococci with elevated minimum inhibitory concentrations (MICs) to ceftriaxone were inconsistently identified phenotypically, with further molecular characterization and ultimate identification of G sanguinis.

Methods

Two clinical strains (from 2 obese women; 1 with a prosthetic hip infection and the other with bacteremia) were analyzed with standard identification methods, followed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry, 16S recombinant ribonucleic acid (rRNA), and sodA polymerase chain reaction (PCR). The existing medical literature on Globicatella also was reviewed.

Results

Standard phenotypic methods failed to consistently identify the isolates. 16S PCR yielded sequences that confirmed Globicatella species. sodA sequencing provided species-level identification of G sanguinis. The review of literature reveals G sanguinis as an increasingly reported cause of infections of the urine, meninges, and blood. To our knowledge, this is the first reported case of an orthopedic infection caused by Globicatella sanguinis. A review of the 37 known cases of G sanguinis infection revealed that 83% of patients are female, and 89% are at the extremes of age (<5 or >65 years).

Conclusions

Globicatella sanguinis, an uncommon pathogen with elevated minimum inhibitory concentrations to third-generation cephalosporins, is difficult to identify by phenotypic methods and typically causes infections in females at the extremes of age. It may colonize skin or mucosal surfaces. Advanced molecular techniques utilizing 16S rRNA with sodA PCR accurately identify G sanguinis.

Characteristics and phylogeny of Bacillus cereus strains isolated from Maari, a traditional West African food condiment

Maari is a spontaneously fermented food condiment made from baobab tree seeds in West African countries. This type of product is considered to be safe, being consumed by millions of people on a daily basis. However, due to the spontaneous nature of the fermentation the human pathogen Bacillus cereus occasionally occurs in Maari. This study characterizes succession patterns and pathogenic potential of B. cereus isolated from the raw materials (ash, water from a drilled well (DW) and potash), seed mash throughout fermentation (0-96h), after steam cooking and sun drying (final product) from two production sites of Maari. Aerobic mesophilic bacterial (AMB) counts in raw materials were of 10(5)cfu/ml in DW, and ranged between 6.5×10(3) and 1.2×10(4)cfu/g in potash, 10(9)-10(10)cfu/g in seed mash during fermentation and 10(7) - 10(9) after sun drying. Fifty three out of total 290 AMB isolates were identified as B. cereus sensu lato by use of ITS-PCR and grouped into 3 groups using PCR fingerprinting based on Escherichia coli phage-M13 primer (M13-PCR). As determined by panC gene sequencing, the isolates of B. cereus belonged to PanC types III and IV with potential for high cytotoxicity. Phylogenetic analysis of concatenated sequences of glpF, gmk, ilvD, pta, pur, pycA and tpi revealed that the M13-PCR group 1 isolates were related to B. cereus biovar anthracis CI, while the M13-PCR group 2 isolates were identical to cereulide (emetic toxin) producing B. cereus strains. The M13-PCR group 1 isolates harboured poly-γ-D-glutamic acid capsule biosynthesis genes capA, capB and capC showing 99-100% identity with the environmental B. cereus isolate 03BB108. Presence of cesB of the cereulide synthetase gene cluster was confirmed by PCR in M13-PCR group 2 isolates. The B. cereus harbouring the cap genes were found in potash, DW, cooking water and at 8h fermentation. The "emetic" type B. cereus were present in DW, the seed mash at 48-72h of fermentation and in the final product, while the remaining isolates (PanC type IV) were detected in ash, at 48-72h fermentation and in the final product. This work sheds light on the succession and pathogenic potential of B. cereus species in traditional West African food condiment and clarifies their phylogenetic relatedness to B. cereus biovar anthracis. Future implementation of GMP and HACCP and development of starter cultures for controlled Maari fermentations will help to ensure a safe product.

Isolation of Kurthia gibsonii from non-gonorrheal urethritis: implications for the pathomechanism upon surveying the literature

The incidence and number of species involved in the spectrum of sexually transmitted infections continue to increase. Laboratories have to be prepared for identification of unusual microbes. In our practice, a male patient had recurring urethritis and balanitis after having repeated unprotected insertive sexual intercourse with female piglets. He also had allergy to scents and some metals, otherwise he showed no general symptoms. Specimens were swabbed from the urethra, inflamed glans, rectum, mouth onto several culture media, subsequently isolates were tested for their morphology, biochemical activity. Kurthia gibsonii was isolated from urethra and glans. No concomitant infection with other microbes was detected, haemoculture was negative. Relying upon antibiotic sensitivity test, he was cured with 2 × 500 mg oral cefuroxime for 15 days, and topical gentamycin cream for 2 months. This is the first reported sexually transmitted, zoonotic infection without generalization by Kurthia spp. We report first the antibiogram of K. gibsonii. Slight differences in the antibiotic sensitivity suggest independent infection and sensitivity of urethral and mucous membrane tissues to distinct K. gibsonii strains. Allergy of the patient might predispose to opportunistic infection. Such aspects ought to be tested in details in further cases.

Co-production of surfactin and a novel bacteriocin by Bacillus subtilis subsp. subtilis H4 isolated from Bikalga, an African alkaline Hibiscus sabdariffa seed fermented condiment

Bikalga is a Hibiscus sabdariffa seed fermented condiment widely consumed in Burkina Faso and neighboring countries. The fermentation is dominated by Bacillus subtilis group species. Ten B. subtilis subsp. subtilis (six isolates) and Bacillus licheniformis (four isolates) isolated from traditional Bikalga were examined for their antimicrobial activity against a panel of 36 indicator organisms including Gram-positive and Gram-negative bacteria and yeasts. The Bacillus spp. isolates showed variable inhibitory abilities depending on the method used. Both Gram-positive and Gram-negative bacteria were inhibited in the agar spot assay while only Gram-positive pathogens were inhibited in the agar well diffusion assay. Cell free supernatants (CFS) of pure cultures of 3 B. subtilis subsp. subtilis (G2, H4 and F1) strains inhibited growth of Listeria monocytogenes, Micrococcus luteus, Staphylococcus aureus and Bacillus cereus, while CFS of 2 B. licheniformis (E3 and F9) strains only inhibited M. luteus. The antimicrobial substance(s) produced by B. subtilis subsp. subtilis H4 was further characterized. The antimicrobial substance(s) produced by H4 was detected from mid-exponential growth phase. The activity was sensitive to protease and trypsin, but resistant to the proteolytic action of proteinase K and papain. Treatment with α-amylase and lipase II resulted in a complete loss of antimicrobial effect, indicating that a sugar moiety and lipid moiety are necessary for the activity. Treatment with mercapto-ethanol resulted in a significant loss, indicative of the presence of disulfide bridges. The antimicrobial activity of H4 was heat resistant and active at pH3-10. PCR detection of yiwB, sboA, spoX, albA and spaS, etnS genes and genes coding for surfactins and plipastatins (fengycins) indicated a potential for subtilosin, subtilin and lipopeptide production, respectively. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) was carried out and a single band of approximately 4kDa had antimicrobial activity. Ultra high performance liquid chromatography-time of flight mass spectrometry (UHPLC-TOFMS) analysis of the 4kDa band allowed identification of surfactin and a protein with a monoisotopic mass of 3346.59Da, which is dissimilar in size to subtilosin and subtilin. Surfactin is a cyclic lipoheptapeptide, which contains a β-hydroxy fatty acid, but no di-sulfide bridges or sugar residues. The complete loss of activity upon amylase treatment indicates that surfactin was not responsible for the observed antimicrobial effect. However, it cannot completely be ruled out that surfactin acts synergistically with the detected protein, though further investigations are needed to confirm this.

Molecular identification and safety of Bacillus species involved in the fermentation of African oil beans (Pentaclethra macrophylla Benth) for production of Ugba

Molecular identification of Bacillus spp. involved in the fermentation of African oil bean seeds for production of Ugba, as well as ability of the Bacillus spp. isolated to produce toxins, were investigated. Forty-nine bacteria were isolated from Ugba produced in different areas of South Eastern Nigeria and identified by phenotyping and sequencing of 16S rRNA, gyrB and rpoB genes. Genotypic diversities at interspecies and intraspecies level of the isolates were screened by PCR amplification of the 16S-23S rDNA intergenic transcribed spacer (ITS-PCR) and repetitive sequence-based PCR (rep-PCR). The ability of the bacteria to produce toxins was also investigated by detection of genes encoding production of haemolysin BL (HblA, HblC, HblD), non-haemolytic enterotoxin (NheA, NheB, NheC), cytotoxin K (CytK) and emetic toxin (EM1) using PCR with specific primers. Moreover, a Bacillus cereus Enterotoxin Reverse Passive Latex Agglutination test kit (BCET-RPLA) was used to screen ability of the isolates to produce haemolysin in broth and during fermentation of African oil bean seeds. The isolates were characterized as motile, rod-shaped, endospore forming, catalase positive, Gram-positive bacteria. They were identified as Bacillus cereus sensu lato (42), Lysinibacillus xylanilyticus (3), Bacillus clausii (1), Bacillus licheniformis (1), Bacillus subtilis (1), and Bacillus safensis (1). B. cereus was the predominant Bacillus species and was present in all samples studied. Using ITS-PCR, interspecies diversity was observed among isolates, with six clusters representing each of the pre-cited species. Rep-PCR was more discriminatory (eight clusters) and allowed further differentiation at intraspecies level for the B. cereus and L. xylanilyticus isolates with two genotypes for each species. Genes encoding production of non-haemolytic enterotoxin (NheA, NheB, NheC) and cytotoxin K (CytK) genes were detected in all B. cereus isolates, while Hbl genes (HblA, HblC, HblD) were detected in only one isolate. The emetic-specific gene fragment was not detected in any of the isolates studied. None of the toxin genes screened was detected in isolates belonging to other Bacillus species. Using RPLA, haemolysin production was detected in one isolate of B. cereus, which showed positive amplicons for Hbl genes, both during cultivation in broth and during fermentation of oil bean seeds.

Inhibition of Bacillus cereus growth by bacteriocin producing Bacillus subtilis isolated from fermented baobab seeds (maari) is substrate dependent

Maari is a spontaneously alkaline fermented food condiment made from baobab tree seeds. Due to the spontaneous nature of maari fermentations growth of the opportunistic human pathogen Bacillus cereus is occasionally observed. Bacillus subtilis strains are important for alkaline seed fermentations because of their enzymatic activities contributing to desirable texture, flavor and pH development. Some B. subtilis strains have antimicrobial properties against B. cereus. In the present work, three bacteriocin producing B. subtilis strains (B3, B122 and B222) isolated from maari were tested. The production of antimicrobial activity by the three strains was found to be greatly influenced by the substrate. All three B. subtilis strains produced antimicrobial activity against B. cereus NVH391-98 in BHI broth as determined by the agar well diffusion assay, whereas no antimicrobial activity was detected in whole cooked baobab seeds and in 10% (w/v) grinded baobab seeds. Incorporation of BHI with up to 5% (w/w) grinded baobab seeds enhanced the antimicrobial activity of B. subtilis compared with pure BHI in a strain dependent manner. Incorporation of BHI with 50% (w/w) baobab grinded seeds decreased the antimicrobial activity. Addition of the inorganic salts FeCl₃, MgSO₄ and MnSO₄ has previously been reported to increase bacteriocin production of B. subtilis, but the addition of these salts to 10% (w/v) grinded baobab seed broth did not cause antimicrobial activity. Survival of B. cereus NVH391-98 in co-culture with B. subtilis was tested in BHI broth, 10% (w/v) grinded baobab seed based broth and during baobab seed fermentation to produce maari. B. cereus NVH391-98 grew well in all three substrates in mono-culture. All the 3 B. subtilis strains were able to decrease B. cereus NVH391-98 to levels below the detection limit (<10 CFU/ml) in BHI, but not in baobab seed based substrates, even though the outgrowth of B. cereus NVH391-98 was delayed by up to 40 h. In conclusion, production of antimicrobial activity by the investigated B. subtilis strains is highly substrate-specific and strain-specific. The three B. subtilis strains delayed but did not prevent B. cereus outgrowth during baobab seed fermentations. Maari is produced through mixed microbial population fermentations. B. subtilis co-starter culture candidates originating from maari which are able to prevent pathogen outgrowth remain to be identified.

Combination of culture-independent and culture-dependent molecular methods for the determination of bacterial community of iru, a fermented Parkia biglobosa seeds

In this study, bacterial composition of iru produced by natural, uncontrolled fermentation of Parkia biglobosa seeds was assessed using culture-independent method in combination with culture-based genotypic typing techniques. PCR-denaturing gradient gel electrophoresis (DGGE) revealed similarity in DNA fragments with the two DNA extraction methods used and confirmed bacterial diversity in the 16 iru samples from different production regions. DNA sequencing of the highly variable V3 region of the 16S rRNA genes obtained from PCR-DGGE identified species related to Bacillus subtilis as consistent bacterial species in the fermented samples, while other major bands were identified as close relatives of Staphylococcus vitulinus, Morganella morganii, B. thuringiensis, S. saprophyticus, Tetragenococcus halophilus, Ureibacillus thermosphaericus, Brevibacillus parabrevis, Salinicoccus jeotgali, Brevibacterium sp. and uncultured bacteria clones. Bacillus species were cultured as potential starter cultures and clonal relationship of different isolates determined using amplified ribosomal DNA restriction analysis (ARDRA) combined with 16S-23S rRNA gene internal transcribed spacer (ITS) PCR amplification, restriction analysis (ITS-PCR-RFLP), and randomly amplified polymorphic DNA (RAPD-PCR). This further discriminated B. subtilis and its variants from food-borne pathogens such as B. cereus and suggested the need for development of controlled fermentation processes and good manufacturing practices (GMP) for iru production to achieve product consistency, safety quality, and improved shelf life.

Genome sequence of Lysinibacillus boronitolerans F1182, isolated from a traditional Korean fermented soybean product

Lysinibacillus is a Gram-positive, rod-shaped, and round-spore-forming bacterial genus of the family Bacillaceae. We analyzed the genome sequence of Lysinibacillus boronitolerans F1182, isolated from a traditional Korean fermented soybean product. The genome sequence contained 4.46 Mbp with a G+C content of 37.5%. This is the first report of an L. boronitolerans genome.

Identification of lactic acid bacteria isolated during traditional fura processing in Ghana

Fura is a millet-based spontaneously fermented dumpling produced and consumed in parts of West Africa, particularly Nigeria, Burkina Faso and Ghana. From eight traditional fura production sites in northern Ghana, 862 lactic acid bacteria were isolated and identified to species level using a combination of genotypic and phenotypic methods including (GTG)(5)-based PCR fingerprinting and 16S rRNA gene sequencing, multiplex PCR by means of recA gene sequence comparison, conventional morphological characteristics and carbohydrate fermentation profiling. During millet dough fermentation, pH decreased from 5.6-6.4 to 4.1-3.7 and total lactic acid bacteria (LAB) counts increased from 4.4-5.3 to 7.9-9.2 log(10) (cfu/g). The initial stages of the fermentation were characterized by co-dominance of homo- and heterofermentative species of Pediococcus acidilactici, Weisella confusa, Lactobacillus fermentum, Lactobacillus reuteri, Lactobacillus salivarius, and Lactobacillus paraplantarum whereas L. fermentum was dominating at the end of the fermentation. L. fermentum was predominant in all fermentations (p < 0.05) and a high uniformity was observed among production sites regarding the dominance of L. fermentum. L. fermentum and W. confusa were isolated in all production sites and almost at all fermentation stages indicating that they are indigenous to traditional fura processing. The other LAB bacteria species which comprised a minor proportion of the total LAB occurred occasionally and in an irregular pattern among the production sites.

Bacteriocin formation by dominant aerobic sporeformers isolated from traditional maari

The antimicrobial activity of 8 Bacillus spp. and 2 Lysinibacillus spp. representing the predominant aerobic sporeformers during traditional maari fermentations, a traditional fermented baobab seeds product from Burkina Faso, was investigated. The antimicrobial activity was assessed against a total of 31 indicator organisms representing various Gram-negative and positive pathogens. The screening showed that 3 Bacillus subtilis strains (B3, B122 and B222) in particular had antimicrobial activity against some Gram-positive organisms and were selected for further studies. It was found that the antimicrobial substances produced were heat stable, in-sensitive to catalase, sensitive to protease and trypsin but resistant to the proteolytic action of papain and proteinase K and equally active at pH values ranging from 3 to 11. Bacteriocin secretion started in late exponential growth phase and maximum activity was detected during the stationary growth phase. The production of bacteriocin by B. subtilis B3, B122 and B222 was dependent on the aeration conditions. Maximum production of bacteriocin was observed under reduced aeration. Specific primers were used to screen isolates B3, B122 and B222 for genes involved in the synthesis of the bacteriocins subtilosin A, subtilin, sublancin and ericin. Amplicons of the expected sizes were detected for iywB, sboA, sboX, albA and spaS involved in the biosynthesis of subtilosin and subtilin, respectively. The translated nucleotide sequences had 100% identity to the YiwB, SboX and SboA amino acid sequences of the subtilosin A producing B. subtilis subsp. subtilis strain 168. Interestingly there was a 3 amino acid deletion at the N-terminal part of AlbA in B3, B122 and B222 that probably alters the activity of this enzyme. Analysis of the spaS gene sequences of B3, B122 and B222, encoding a subtilin precursor peptide, showed that the translated nucleotide sequence had 98% identity with the corresponding SpaS amino acid sequence of subtilin producing B. subtilis subsp. spizizenii strain ATCC6633.

Diversity of bacteria and yeast in the naturally fermented cotton seed and rice beverage produced by Brazilian Amerindians

Microorganisms associated with the fermentation of cotton seed and rice were studied using a combination of culture-dependent and -independent methods. Samples of the cotton seed and rice beverage were collected every 8 h during the fermentation process for analysis of the microbiota present over 48 h. The lactic acid bacteria (LAB) population reached values of approximately 8.0 log cfu/mL. A total of 162 bacteria and 81 yeast isolates were identified using polyphasic methods. LAB (Lactobacillus plantarum, Lactobacillus vermiforme, Lactobacillus paracasei) were the most frequently isolated bacteria. Bacillus subtilis was present from 16 h until the end of the fermentation process. A decrease in pH value from 6.92 (0 h) to 4.76 (48 h) was observed, and the concentration of lactic acid reached 24 g/L at the end of the fermentation process. DGGE (denaturing gradient gel electrophoresis) was performed to determine the dynamics of the communities of bacteria and yeast, and the analysis revealed a predominance of LAB throughout the fermentation process. No changes were observed in the yeast community. The yeast species detected were Candida parapsilosis, Candida orthopsilosis, Clavispora lusitaniae and Rhodotorula mucilaginosa. Our studies indicate that the DGGE technique combined with a culture-dependent method is required to discern the dynamics in the fermentation of cotton seed and rice.