Exopolysaccharide Produced by Probiotic Bacillus albus DM-15 Isolated From Ayurvedic Fermented Dasamoolarishta: Characterization, Antioxidant, and Anticancer Activities

An exopolysaccharide (EPS) was purified from the probiotic bacterium Bacillus albus DM-15, isolated from the Indian Ayurvedic traditional medicine Dasamoolarishta. Gas chromatography-mass spectrophotometry and nuclear magnetic resonance (NMR) analyses revealed the heteropolymeric nature of the purified EPS with monosaccharide units of glucose, galactose, xylose, and rhamnose. Size-exclusion chromatography had shown the molecular weight of the purified EPS as around 240 kDa. X-ray powder diffraction analysis confirmed the non-crystalline amorphous nature of the EPS. Furthermore, the purified EPS showed the maximum flocculation activity (72.80%) with kaolin clay and emulsification activity (67.04%) with xylene. In addition, the EPS exhibits significant antioxidant activities on DPPH (58.17 ± 0.054%), ABTS (70.47 ± 0.854%) and nitric oxide (58.92 ± 0.744%) radicals in a concentration-dependent way. Moreover, the EPS showed promising cytotoxic activity (20 ± 0.97 μg mL^–1) against the lung carcinoma cells (A549), and subsequent cellular staining revealed apoptotic necrotic characters in damaged A549 cells. The EPS purified from the probiotic strain B. albus DM-15 can be further studied and exploited as a potential carbohydrate polymer in food, cosmetic, pharmaceutical, and biomedical applications.

Salivary Proteome Profile of Women during Fertile Phase of Menstrual Cycle as Characterized by Mass Spectrometry

Objectives:

Ovulation is such a critical physiological process that its noninvasive detection based on salivary constituents has several advantages in humans. Hence, the present study is proposed to identify the ovulatory-specific proteins in saliva in order to detect ovulation phase.

Materials and Methods:

Samples were collected from women volunteers. The procedure adopted was approved by the Institutional Human Ethical Committee (DM/2014/101/38), Bharathidasan University. The saliva samples were collected from thirty healthy female volunteers, with a prior written consent. One-way analysis of variance was used to calculate protein concentration and band intensity using SPSS 16 software (SPSS Inc., Cary, NC, USA). The salivary protein expression pattern during different phases of menstrual cycle was analyzed using gel-based high resolution-liquid chromatography-mass spectrometry/mass spectrometry and matrix-assisted laser desorption ionization-time of flight/time of flight. Further, bioinformatics tools were adopted to annotate the proteins identified at various phases of menstrual cycle.

Results:

As many as 530 proteins showed up in the saliva during ovulatory phase, whereas there were only 251 proteins identified during postovulatory phase. The functional annotation of salivary proteins revealed that the proteins got assigned to the class of “extracellular proteins” which are concerned with regulatory functions. The 16 unique and/or differentially expressed protein spots appeared during ovulatory phase, among which Cystatin-S, Prolactin-inducible protein, Cystatin-A, Cystatin-SN, BPI fold-containing family A member 2, Alpha-tubulin N-acetyltransferase 1, Carbonic anhydrase-6, Protein LEG1 homolog, Hemoglobin subunit beta, and Pancreatic alpha-amylase were identified.

Conclusion:

Total salivary proteome profile has been listed with respect to various phases of menstrual cycle. Among the protein listed, Cystatin-S offers a biomarker protein and/or indicator of ovulatory phase. However, extensive validation is required before arriving to a candidate bio-marker protein.

Structural characterization, functional and biological activities of an exopolysaccharide produced by probiotic Bacillus licheniformis AG-06 from Indian polyherbal fermented traditional medicine

An exopolysaccharide (EPS) was purified from the probiotic bacterium Bacillus licheniformis AG-06 isolated from the polyherbal fermented traditional medicine (Ashwagandharishta) of Indian Ayurveda. High-performance liquid chromatography (HPLC) based compositional analysis exhibits the heteropolymeric nature of the EPS consisting of galactose, rhamnose, xylose, mannose, and glucose, as the monomeric units. Fourier-transform infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopic analyses confirm the presence of typical carbohydrate polymer functional groups and structural units, respectively. The purified EPS demonstrates the web-like fibrous and porous nature in scanning electron microscopic and atomic force microscopic studies. The purified EPS had shown 71.83% and 67.79% of flocculation and emulsification activities, respectively. Antioxidant activity was evaluated against 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), nitric oxide, and superoxide free radicals and the scavenging actions were increased in a dose-dependent manner. Moreover, the purified EPS exhibits a significant cytotoxic activity against the human lung carcinoma cells (A549), which strongly suggests the anticancer potential of the EPS derived from B. licheniformis AG-06.

Microbial biodiesel production from oil palm biomass hydrolysate using marine Rhodococcus sp. YHY01

The effect of various biomass derived inhibitors (i.e. furfural, hydroxymethylfurfural (HMF), vanillin, 4-hydroxy benzaldehyde (4-HB) and acetate) was investigated for fatty acid accumulation in Rhodococcus sp. YHY 01. Rhodococcus sp. YHY01 was able to utilize acetate, vanillin, and 4-HB for biomass production and fatty acid accumulation. The IC₅₀ value for furfural (3.1mM), HMF (3.2mM), vanillin (2.0mM), 4-HB (2.7mM) and acetate (3.7mM) was calculated. HMF and vanillin affect fatty acid composition and increase saturated fatty acid content. Rhodococcus sp. YHY 01 cultured with empty fruit bunch hydrolysate (EFBH) as the main carbon source resulted in enhanced biomass (20%) and fatty acid productivity (37%), in compression to glucose as a carbon source. Overall, this study showed the beneficial effects of inhibitory molecules on growth and fatty acid production, and support the idea of biomass hydrolysate utilization for biodiesel production by avoiding complex efforts to remove inhibitory compounds.

Biomass-derived molecules modulate the behavior of Streptomyces coelicolor for antibiotic production

Various chemicals, i.e., furfural, vanillin, 4-hydroxybenzaldehyde and acetate produced during the pretreatment of biomass affect microbial fermentation. In this study, effect of vanillin, 4-hydroxybenzaldehyde and acetate on antibiotic production in Streptomyces coelicolor is investigated. IC₅₀ value of vanillin, 4-hydroxybenzaldehyde and acetate was recorded as 5, 11.3 and 115 mM, respectively. Vanillin was found as a very effective molecule, and it completely abolished antibiotic (undecylprodigiosin and actinorhodin) production at 1 mM concentration, while 4-hydroxybenzaldehyde and acetate have little effect. Microscopic analysis with field emission scanning electron microscopy (FESEM) showed that addition of vanillin inhibits mycelia formation and increases differentiation of S. coelicolor cells. Vanillin increases expression of genes responsible for sporulation (ssgA) and decreases expression of antibiotic transcriptional regulator (redD and actII-orf4), while it has no effect on genes related to the mycelia formation (bldA and bldN) and quorum sensing (scbA and scbR). Vanillin does not affect the glycolysis process, but may affect acetate and pyruvate accumulation which leads to increase in fatty acid accumulation. The production of antibiotics using biomass hydrolysates can be quite complex due to the presence of exogenous chemicals such as furfural and vanillin, and needs further detailed study.

Medium engineering for enhanced production of undecylprodigiosin antibiotic in Streptomyces coelicolor using oil palm biomass hydrolysate as a carbon source

In this study, a biosugar obtained from empty fruit bunch (EFB) of oil palm by hot water treatment and subsequent enzymatic saccharification was used for undecylprodigiosin production, using Streptomyces coelicolor. Furfural is a major inhibitor present in EFB hydrolysate (EFBH), having a minimum inhibitory concentration (MIC) of 1.9mM, and it reduces utilization of glucose (27%), xylose (59%), inhibits mycelium formation, and affects antibiotic production. Interestingly, furfural was found to be a good activator of undecylprodigiosin production in S. coelicolor, which enhanced undecylprodigiosin production by up to 52%. Optimization by mixture analysis resulted in a synthetic medium containing glucose:furfural:ACN:DMSO (1%, 2mM, 0.2% and 0.3%, respectively). Finally, S. coelicolor was cultured in a fermenter in minimal medium with EFBH as a carbon source and addition of the components described above. This yielded 4.2μg/mgdcw undecylprodigiosin, which was 3.2-fold higher compared to that in un-optimized medium.

Ketide Synthase (KS) Domain Prediction and Analysis of Iterative Type II PKS Gene in Marine Sponge-Associated Actinobacteria Producing Biosurfactants and Antimicrobial Agents

The important biological macromolecules, such as lipopeptide and glycolipid biosurfactant producing marine actinobacteria were analyzed and their potential linkage between type II polyketide synthase (PKS) genes was explored. A unique feature of type II PKS genes is their high amino acid (AA) sequence homology and conserved gene organization. These enzymes mediate the biosynthesis of polyketide natural products with enormous structural complexity and chemical nature by combinatorial use of various domains. Therefore, deciphering the order of AA sequence encoded by PKS domains tailored the chemical structure of polyketide analogs still remains a great challenge. The present work deals with an in vitro and in silico analysis of PKS type II genes from five actinobacterial species to correlate KS domain architecture and structural features. Our present analysis reveals the unique protein domain organization of iterative type II PKS and KS domain of marine actinobacteria. The findings of this study would have implications in metabolic pathway reconstruction and design of semi-synthetic genomes to achieve rational design of novel natural products.

Metal removal and reduction potential of an exopolysaccharide produced by Arctic psychrotrophic bacterium Pseudomonas sp. PAMC 28620

Metal reducing potential of an exopolysaccharide (EPS) produced by Arctic glacier soil bacteriumPseudomonassp. PAMC 28620.

Biotransformation of lysine into cadaverine using barium alginate-immobilized Escherichia coli overexpressing CadA

In this study, Escherichia coli cells overexpressing lysine decarboxylase (CadA) were used for cadaverine production. Barium alginate was selected as a matrix for immobilization of E. coli YH91. Free cells and immobilized cells (IC) were characterized for their physiochemical properties, and the optimum pH and temperature were determined as 6 and 37 °C, respectively. Immobilized cells were three times more thermally stable compared to free cells at the optimum temperature and had a half-life (t 1/2) of 131 h. The free cells lost most of lysine decarboxylase activity after nine cycles, but in contrast immobilized cells retained 56% of their residual activity even after the 18th cycle. The immobilized cells gave a maximum production of cadaverine (75.8 g/L) with 84% conversion.

Overexpression of succinyl-CoA synthase for poly (3-hydroxybutyrate-co-3-hydroxyvalerate) production in engineered Escherichia coli BL21(DE3)

AIM

This study aims to increase the 3-hydroxyvalerate (3HV) fraction in poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(HB-co-HV)] using succinyl-CoA synthase.

METHODS AND RESULTS

Escherichia coli YH090, a polyhydroxyalkonate (PHA)-producing strain, was further engineered for overexpression of succinyl-CoA synthase genes (sucCD), and examined for P(HB-co-HV) copolymer production in the presence of various precursor molecules using mixture analysis. Glycerol, succinate and propionate were screened as important factors for controlling intracellular PHA accumulation and monomer composition. Glycerol concentrations exerted the greatest influence on the overall biomass concentration and the intracellular PHA content, while propionate concentrations in the presence of succinate influenced the 3HV content of the copolymer. Mixture analysis also demonstrated that the engineered strain has the capacity to accumulate up to 80% of its cell dry weight (CDW) as PHA with a variable fraction of 3HV monomer (maximum of 72 wt %) depending on the controlled conditions.

CONCLUSIONS

Propionate is the principal precursor for 3HV monomer in P(HB-co-HV) biopolymer and its utilization requires conversion to propionyl-CoA. Engineered E. coli YHY99, overexpressing sucCD genes, leads to an increase of the succinyl-CoA pool, which enhances the conversion rate of propionate by providing a CoA supply to other acyltransferase enzymes that have a role in propionate utilization.

SIGNIFICANCE AND IMPACT OF THE STUDY

Engineered E. coli YHY99 was able to utilize propionate with a 4·5-fold increase in rate, as compared to the control strain, and resulted in the synthesis of a copolymer with high 3HV monomer content.

Formulation of iron oxide nanoparticles using exopolysaccharide: evaluation of their antibacterial and anticancer activities

Formulation of FeONPs using bacterial exopolysaccharide and their significance.

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.

Synthesis of carbohydrate polymer encrusted gold nanoparticles using bacterial exopolysaccharide: a novel and greener approach

A novel report on synthesis of gold nanoparticles using bacterial exopolysaccharide and synthesized nanocrystals (5–20 nm) capped with polysaccharide layer.

Optimization and production of pyrrolidone antimicrobial agent from marine sponge-associated Streptomyces sp. MAPS15

Twenty-nine actinobacterial strains were isolated from marine sponge Spongia officinalis and screened for antagonistic activity against various bacterial and fungal pathogens. The active antibiotic producer MAPS15 was identified as Streptomyces sp. using 16S rRNA phylogenetic analysis. The critical control factors were selected from Plackett-Burman (PB) factorial design and the bioprocess medium was optimized by central composite design (CCD) for the production of bioactive metabolite from Streptomyces sp. MAPS15. The maximum biomass and active compound production obtained with optimized medium was 6.13 g/L and 62.41 mg/L, respectively. The economical carbon source, paddy straw was applied for the enhanced production of bioactive compound. The purified active fraction was characterized and predicted as pyrrolidone derivative which showed broad spectrum of bioactivity towards indicator organisms. The predicted antimicrobial spectra suggested that the Streptomyces sp. MAPS15 can produce a suite of novel antimicrobial drugs.

Optimization of polyhydroxybutyrate production by marine Bacillus megaterium MSBN04 under solid state culture

A marine sponge-associated bacterium Bacillus megaterium MSBN04 was used for the production of polyhydroxybutyrate (PHB) under solid state culture (SSC). A central composite design (CCD) was employed to optimize the production medium and to find out the interactive effects of four independent variables, viz. tapioca industry waste, palm jaggery, horse gram flour and trace element solution on PHB production. The maximum yield of PHB 8.637 mg g(-1) of substrate (tapioca industry waste) was achieved from biomass 15.203 mg g(-1) of substrate, using statistically optimized medium. The horse gram flour (nitrogen source) and trace element solution were found to be critical control factors for PHB synthesis. The (1)H NMR analysis revealed that the polymer was a PHB monomer. PHB obtained from this study having high molecular weight (6.7×10(5) Da) with low polydispersity index (PDI) value (1.71) and produced PHB was used to synthesize PHB polymeric nanoparticles using solvent displacement approach. Therefore, B. megaterium MSBN04 is an ideal candidate that can be exploited biotechnologically for the commercial production of PHB under solid state culture.

A statistical approach for optimization of polyhydroxybutyrate production by marine Bacillus subtilis MSBN17

The important biological macromolecule polyhydroxybutyrate (PHB) producing Bacillus subtilis was isolated from the marine sponge Callyspongia diffusa and identified by means of 16S rRNA analysis. The central composite design (CCD) was used to optimize the PHB production using cheap raw materials such as pulp industry waste (PIW), tamarind kernel powder (TKP), palm jaggery (PJ) and green gram flour (GGF). The extracted polymer was characterized by (1)H NMR analysis. The PIW was fed at three different intervals and the maximum production of PHB (19.08g/L) was attained after a period of 40h of incubation of B. subtilis. Dissolved oxygen, sodium chloride and nitrogen source were found to be the critical control factors that affected the PHB polymer production. The present investigation demonstrates an inexpensive model of producing PHB green thermoplastics in vitro for biomedical applications.

Synthesis of silver nanoparticles by polysaccharide bioflocculant produced from marine Bacillus subtilis MSBN17

The polysaccharides are emerging as stabilizing and reducing agents for nanoparticles synthesis, however the commercial polysaccharides are not economically viable. Therefore, the exopolysaccharide from microbial origin such as bioflocculants are promising alternate for the synthesis and stabilization of nanoparticles. In this report, a bioflocculant (MSBF17) was produced from marine sponge-associated Bacillus subtilis MSBN17 under submerged fermentation using the economical substrates. The production was statistically optimized with most significant factors such as palm jaggery, NH(4)NO(2), K(2)HPO(4) and NaCl. The maximum bioflocculant production obtained with statistically optimized medium was 13.42 g/l. Based on the biochemical composition and FT-IR analysis, the flocculant compound was predicted as a polysaccharide derivative. The flocculating activity of the MSBF17 was invariably considerable at high salinity and temperature. It was found that the nano-scale silver can be synthesized in reverse micelles using the bioflocculant as stabilizer. The silver nanoparticles (AgNPs) were characterized by UV-spectroscopy, FT-IR and TEM analysis. The AgNPs were spherical shaped (60 nm) and stable for 5 months. Therefore, the bioflocculant-mediated synthesis of nanomaterials can be considered as environmental benign greener approach.