Process optimization and production of polyhydroxybutyrate using palm jaggery as economical carbon source by marine sponge-associated Bacillus licheniformis MSBN12

Controlled release of trifluralin herbicide using luminescent Vibrio-derived polyhydroxyalkanoate (PHA) microcapsules

The controlled release of herbicides using new and safe materials can mitigate environmental pollution. Polyhydroxyalkanoate (PHA) is a type of biopolymer that can be produced by various bacteria. It has properties that make it suitable for encapsulation and controlled release applications. A luminescent bacterium, Vibrio sp. VLC strain was used as the PHA producer in this study. Initially, the polymer was synthesized by the bacterium following optimization of the culture medium, resulting in an approximate yield of 25 %. Subsequently, the produced polymer was analyzed using TEM, FTIR, and H-NMR techniques. Microcapsules were produced using the emulsion method. FE-SEM imaging revealed spherical microcapsules with an average diameter of 0.5-2 μm. The herbicide loading content and encapsulation efficiency were determined to be 16.64 % and 66.56 %, respectively. The herbicidal effect of the microcapsules containing trifluralin was investigated using Amaranthus retroflexus and Setaria viridis plants, demonstrating a significant reduction in various parameters after application. Furthermore, the impact of encapsulated herbicide on soil microbial population was assessed, revealing a less negative effect compared to its free form. These findings suggest that the PHA from a luminescent vibrio holds promise as an eco-friendly, biodegradable, nontoxic material for the controlled release of herbicides.

Strategic nutrient sourcing for biomanufacturing intensification

The successful design of economically viable bioprocesses can help to abate global dependence on petroleum, increase supply chain resilience, and add value to agriculture. Specifically, bioprocessing provides the opportunity to replace petrochemical production methods with biological methods and to develop novel bioproducts. Even though a vast range of chemicals can be biomanufactured, the constraints on economic viability, especially while competing with petrochemicals, are severe. There have been extensive gains in our ability to engineer microbes for improved production metrics and utilization of target carbon sources. The impact of growth medium composition on process cost and organism performance receives less attention in the literature than organism engineering efforts, with media optimization often being performed in proprietary settings. The widespread use of corn steep liquor as a nutrient source demonstrates the viability and importance of "waste" streams in biomanufacturing. There are other promising waste streams that can be used to increase the sustainability of biomanufacturing, such as the use of urea instead of fossil fuel-intensive ammonia and the use of struvite instead of contributing to the depletion of phosphate reserves. In this review, we discuss several process-specific optimizations of micronutrients that increased product titers by twofold or more. This practice of deliberate and thoughtful sourcing and adjustment of nutrients can substantially impact process metrics. Yet the mechanisms are rarely explored, making it difficult to generalize the results to other processes. In this review, we will discuss examples of nutrient sourcing and adjustment as a means of process improvement.

ONE-SENTENCE SUMMARY

The potential impact of nutrient adjustments on bioprocess performance, economics, and waste valorization is undervalued and largely undercharacterized.

Bacillus cereus saba.zh, a novel bacterial strain for the production of bioplastic (polyhydroxybutyrate)

The identification of novel bacterial strains with a high production potential of polyhydroxybutyrate (PHB) to substitute the bioplastics with non-biodegradable plastics and reducing environmental pollution is really effective. The present study was done with the purpose of PHB bioplastic production using a novel bacterial strain. Twenty-one different bacterial isolates were obtained from petrochemical wastewater, which among them, 10 isolates were PHB positive. The presence of PHB granules was detected in the isolates using Sudan Black B staining. The most excellent PHB-accumulating bacterium with a maximum yield of PHB (61.53%) was selected and identified as Bacillus cereus saba.zh, based on morphological, biochemical, and molecular techniques. 16S rRNA nucleotide sequence of the bacterium was assigned accession number: MT975245 in the NCBI database. The phylogenetic tree data showed that the closest type strain to the Bacillus cereus saba.zh is the Bacillus cereus SDB4 (91%). The three genes (phaA, phaB, and phaC) responsible for the PHB biosynthesis were amplified using the specific oligonucleotide primers by PCR technique. The highest PHB yield was achieved when the culture medium was supplemented with 3% sugarcane molasses as a carbon source, ammonium sulfate as the nitrogen source, at pH 7, and temperature of 30 °C. The characterization of the extracted polymer by FTIR and ¹H NMR spectroscopy proves the presence of methyl, methylene, methine, hydroxyl, and ester carbonyl groups and confirmed the structure of biopolymer as PHB. The novel strain Bacillus cereus saba.zh has good potential as an appropriate candidate for low-cost industrial production of bioplastic.

Bacillus rugosus sp. nov. producer of a diketopiperazine antimicrobial, isolated from marine sponge Spongia officinalis L

A novel Gram-positive and endospore-forming bacterium assigned as strain SPB7^T which is also a new source of a cyclic diketopiperazine (3S,6S)-3,6-diisobutylpiperazine-2,5-dione is described. A polyphasic (biochemical, phenotypic and genotypic) approach was used to clarify the taxonomic affiliation of this strain. The partial and complete 16S rRNA gene sequences revealed that strain SPB7^T is a member of the Bacillus genus [showing high similarity (> 98.70%) with Bacillus spizizenii NRRL B-23049^T, Bacillus tequilensis KCTC 13622^T, Bacillus inaquosorum KCTC 13429^T and Bacillus cabrialesii TE3^T]. The maximum values for average nucleotide identity (ANI) and in silico DNA-DNA hybridization (GGDC, Formula 2) of strain SPB7^T was obtained for twenty-five strains of Bacillus spizizenii (ANI 95.01-95.48% and GGDC 62.70-60.00%). The whole-genome phylogenetic relationship showed that SPB7^T formed an individual and separated clade with the Bacillus spizizenii group. Principal cellular fatty acids identified in strain SPB7^T were anteiso C_15:0, anteiso C_17:0, iso C_15:0, iso C_17:0, C_16:0, C_10:0 3OH and iso C_{17:1 ϖ10c}. Polar lipid profile showed presence of diphosphotidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, two unknown phospholipids and five unknown lipids. Cells were rod shaped, catalase, oxidase-positive and motile. Growth occurred at 20-45 °C (optimal 35 °C), at pH 6.0-10.0 (optimal pH 8) and 0-10% (w/v) NaCl (optimal 2%). The phenotypic, biochemical, and genotypic traits of strain SPB7^T strongly supported its taxonomic affiliation as a novel species of the Bacillus genus, for which the name Bacillus rugosus sp. nov. is proposed. The type strain is SPB7^T (= NRRL B-65559^T, = CICC 24827^T, = MCC 4185^T).

Marine sponge microbial association: Towards disclosing unique symbiotic interactions

Sponges are sessile benthic filter-feeding animals, which harbor numerous microorganisms. The enormous diversity and abundance of sponge associated bacteria envisages sponges as hot spots of microbial diversity and dynamics. Many theories were proposed on the ecological implications and mechanism of sponge-microbial association, among these, the biosynthesis of sponge derived bioactive molecules by the symbiotic bacteria is now well-indicated. This phenomenon however, is not exhibited by all marine sponges. Based on the available reports, it has been well established that the sponge associated microbial assemblages keep on changing continuously in response to environmental pressure and/or acquisition of microbes from surrounding seawater or associated macroorganisms. In this review, we have discussed nutritional association of sponges with its symbionts, interaction of sponges with other eukaryotic organisms, dynamics of sponge microbiome and sponge-specific microbial symbionts, sponge-coral association etc.

First report on isolation of 2,3,4-trihydroxy-5-methylacetophenone from palmyra palm (Borassus flabellifer Linn.) syrup, its antioxidant and antimicrobial properties

The first report on isolation and characterization of 2,3,4-trihydroxy-5-methylacetophenone (1), nicotinamide (2), and uracil (3) from palmyra palm syrup is described. Total phenolic content (TPC) and Total flavonoid content (TFC) of palm syrup were 244.70±5.77(mggallic acid/kg of syrup) and 658.45±27.86(mg quercetin/kg of syrup), respectively. Compound 1 exhibited DPPH radical scavenging activity with an IC₅₀ value of 20.02±0.14μM which was better than ascorbic acid (IC₅₀=22.59±0.30μM). Compound 1 also showed broad spectrum antibacterial activity against Escherichia coli, Mycobacterium smegmatis, Staphylococcus aureus and Staphylococcus simulans.

Exopolysaccharide from psychrotrophic Arctic glacier soil bacterium Flavobacterium sp. ASB 3-3 and its potential applications

Exopolysaccharide from psychrotrophic Arctic glacier soil bacteriumFlavobacteriumsp. ASB 3-3.