Production Of Antibacterial Metabolites Research Articles

Anti-bacterial effects, and metabolites derived from bifidobacterial fermentation of an exopolysaccharide of Cs-HK1 medicinal fungus

This study was to investigate the antibacterial effects and metabolites derived from bifidobacterial fermentation of an exopolysaccharide EPS-LM produced by a medicinal fungus Cordyceps sinensis, Cs-HK1. EPS-LM was a partially purified polysaccharide fraction which was mainly composed of Man, Glc and Gal at 7.31:12.95:1.00 mol ratio with a maximum molecular weight of 360 kDa. After fermentation of EPS-LM in two bifidobacterial cultures, B. breve and B. longum, the culture digesta showed significant antibacterial activities, inhibiting the proliferation and biofilm formation of Escherichia coli. Based on untargeted metabolomic profiling of the digesta, the levels of short chain fatty acids, carboxylic acids, benzenoids and their derivatives were all increased significantly (p < 0.01), which probably contributed to the enhanced antibacterial activity by EPS-LM. Since EPS-LM was only slightly consumed for the bifidobacterial growth, it mainly stimulated the biosynthesis of bioactive metabolites in the bifidobacterial cells. The results also suggested that EPS-LM polysaccharide may have a regulatory function on the bifidobacterial metabolism leading to production of antibacterial metabolites, which may be of significance for further exploration.

Antibacterial metabolites production by Lactobacillus plantarum PTCC 1896 in fermented whey and optimization of fermentation conditions for maximum production using RSM

The aim of the present study was to determine the best conditions for production of antibacterial metabolites by Lactobacillus plantarum PTCC 1896 cultured in whey by optimizing incubation time (24, 48 & 72 h), inoculum size (2, 4 & 6%) and MPC concentration (0, 1 & 2%) using Central Composite Design. During fermentation, due to the production of organic acids, pH decreased to 4.83–3.69 and acidity increased to 0.4–0.96%. Inoculum size and MPC concentration had a positive effect on the cell viability and viability decreased with increasing time (p < 0.05). The addition of MPC to whey up to 1% increased the amount of lactose and nitrogenic sources in medium and helped to produce of antibacterial compounds. The optimal fermentation condition to maximum antibacterial metabolites production was 72 h incubation, 1% MPC concentration and 6% inoculum size. The results of LC–MS analysis confirmed the presence of antibacterial peptides in medium.

Allochthonous rhizobacterial inoculation of Vigna radiata promotes plant growth and anti-bacterial metabolite production

In the present study, rhizobacterial strains associated with paddy rhizosphere were screened for plant growth promotion efficacy against Vigna radiata. Plant growth promotion effect was determined by measuring indole acetic acid (IAA) phosphate solubilisation efficacy and antagonistic activity. Among the isolates, Azosprillum strain AZOSP -V1 strain (114.2 μg/mL) and the AZOSP-S1 strain (104.2 μg/mL) were known to produce maximum production of IAA. High phosphate solubilisation efficacy was recorded in the Pseudomonas fluorescens- PS-V4 strain. Antagonistic activity of rhizobacterial isolates was tested against plant pathogenic fungal strains Pythium sp, Fusarium oxysporum, Rhizoctonia solani and Trichosporium vesiculosum. Among the rhizobacterial strains, notable growth inhibition of all the tested fungal pathogens was recorded in Pseudomonas fluorescens and Bacillus megaterium treatment. Seed priming of the respective rhizobacterial strain supported seedlings' emergence plant growth promotion of V. radiata without inducing any undesirable oxidative stress. Further, rhizobacterial strains were screened for bioactive metabolites production. Among the strains, bioactive metabolites were extracted from Pseudomonas fluorescens strain PS-V4 which showed potential pesticidal and antibacterial activity against gram pod borer Helicoverpa armigera and plant pathogenic bacterial strain Xanthomonas campestris. Biocompatibility of the metabolites was also screened with the zebrafish model by measuring embryonic toxicity. No sign of toxic effect on all the embryonic stages of zebrafish treatment confirmed the best biocompatibility. The present study suggests the possible utilisation of allochthonous rhizobacteria as an effective biofertiliser and biocontrol agent to their high growth promotion, biocontrol efficacy, and coupled oxidative stress modulation.

Optimization of Antibacterial Metabolite Production and Antioxidant Activity of Endophytic Fungi Isolate from Kelakai (Stenochlaena palustris)

This research aims to optimize the production of antibacterial metabolites and test the antioxidant activity of endophytic isolates from kelakai (Stenochlaena palustris). The research results showed that the optimum growth profile of the isolate showed that exponential growth only started on day 1 and reached a maximum on day 17. Based on pH variations, it shows that pH 7 is the optimum pH in inhibiting bacterial growth, and based on variations in carbon sources, it shows that fructose is a better carbon source than glucose. Antimicrobial activity test using ethyl acetate extract from endophytic fungal fermentate based on differences in pH and carbon source showed antimicrobial activity against S. aureus and E. coli with the inhibition zone diameters being 13.50 mm and 11.35 mm, respectively.

OPTIMIZATION OF LACTOBACILLUS PLANTARUM FERMENTATION FOR ENHANCED PHENOLIC PRODUCTION FROM EXTRACT OF BAJAKAH BARK (UNCARIA NERVOSA) BY RESPONSE SURFACE METHODOLOGY

Objective: This research was purposed to optimize the fermentation medium and condition of Lactobacillus plantarum to enhance the production of phenolic compounds with the antibacterial activity tested against Propionibacterium acnes and the optimum conditions of bajakah bark fermentation using Response Surface Method (RSM) methods.&#x0D; Methods: The antibacterial activity test ethanolic extract of bajakah bark was assayed using the agar diffusion perforator method and fermentation method using L. plantarum. Measurement of phenolic content fermentation and without fermentation was done using the standard methods with gallic acid as standard. The optimum conditions of bajakah bark fermentation using RSM methods using Software Design Expert 10.0.0.1.&#x0D; Results: As the result, Response surface analysis revealed the optimum values of the tested significant variables for the production of phenolic were extracted in a concentration 40% (w/v) and 30% (w/v) sucrose for 3 d fermentation period. Under this optimal condition, the phenolic compounds were improved from 10.66 to 18.46 mg GAE/g extract. As well as the antibacterial activity of the fermented extract was increased by 1.35 times compared to the non-fermented extract.&#x0D; Conclusion: In summary that, the optimized fermentation condition could be helpful for the production of antibacterial metabolites from bajakah bark by L. plantarum.

Optimization of cultural conditions for biomass and antibacterial metabolite production by Aspergillus fumigatus strain MF1

The interest of this work is to study the optimized conditions for antibacterial secondary metabolites from the fungus Aspergillus fumigatus strain MF1 extract. The secondary metabolites such as alkaloids, phenols, terpenoids, toxins and ketones are fascinating in the growth of antimicrobial performance of derived compound from strain MF1 extract in addition to the production of biomass. Hence, there is a need to optimize the conditions like temperature, salt concentration, radiation and pH of culture media to enhance the production of biomass and antibacterial metabolite. However, in this study, the authors examined the antibacterial performance of eight bacterial isolates and results showed that Potato dextrose broth (PDB) for seven days incubation at 30 ​°C temperature, pH-6, maltose (carbon source), yeast extract (nitrogen source), and 5% NaCl is the optimized parameters for high yielding of biomass and antibacterial secondary metabolites by A. fumigatus MF1 extract.

Tapping into Tapajos: antibacterial potential of fungal strains isolated from decaying wood in the Brazilian Amazon.

The emergence of bacterial resistance to antimicrobials poses a significant health threat. To address this issue, exploring the fungal diversity in freshwater environments in the Amazon Forest has potential in the search for new antimicrobials. This study aimed to investigate the production of antibacterial metabolites by aquatic fungi from Amazon lakes, specifically Lake Juá and Lake Maicá (Brazil-PA). The fungal isolates were obtained from wood fragments submerged in these lakes, and the ethyl acetate extracts were evaluated for antibacterial activity against Staphylococcus aureus ATCC 25923, S. aureus (MRSA), ATCC 43300, Escherichia coli ATCC 25922, and E. coli (ESBL) NCTC 13353. Additionally, toxicity of the extracts (EtOAc with antimicrobial activity) against human fibroblasts MRC-5 was investigated. The study identified 40 fungal strains with antimicrobial screening, and the ethyl acetate extracts of Fluviatispora C34, Helicascus C18, Monodictys C15, and Fusarium solani LM6281 exhibited antibacterial activity. F. solani LM6281 showed the lowest minimum inhibitory concentration (MIC) of 50 µg/mL against S. aureus strains and MIC of 100 µg/mL against E. coli strains including ESBL. The cytotoxicity (IC50) of the extract (EtOAc) of F. solani LM6281 was 34.5 µg/mL. Preliminary studies of the TLC culture and RNM-H from the extract (EtOAc) of F. solani suggested the presence of substances from the class of terpenes, quinones, phenolics, and flavonoids. This study highlights the potential of submerged wood fungi in the Amazon region to produce antibacterial substances, thus identifying them as sources of novel bioactive compounds with potential use in the pharmaceutical industry and regional bioeconomy.

An endophytic Streptomyces sp. DARP-7 isolated from coastal lichen and enhancement of its antibacterial metabolite production using response surface methodology

Actinomycete DARP-7 was isolated from the coastal foliose lichen Dirinaria aegilita (Afzel.ex Ach.) B.J.Moore and identified as Streptomyces sp. using 16S rRNA sequencing. Among the eight culture media used for antimicrobial metabolite production, the peptone yeast extract iron medium (ISP-6) showed higher production with the maximum zone of inhibition (12 mm) against Staphylococcus aureus . Further, the ISP-6 medium components were optimized through the Plackett-Burman design (PBD) followed by Response Surface Methodology (RSM). Yeast extract, sodium thiosulphate, and ferric ammonium citrate would play a significant role in antibiotic production. Further, the significant variables from PBD were optimized through Central Composite Design (CCD) of RSM for enhanced antibiotic production. The optimal medium components were found to be peptone - 15 (g/L), protease peptone - 5 (g/L), yeast extract - 2.915 (g/L), ferric ammonium citrate - 0.651 (g/L), K 2 HPO 4 – 1 (g/L) and Na 2 S 2 O 3 – 0.155 (g/L), respectively. The optimized result was validated and the antibacterial activity against S. aureus increased upto 19.9 mm (66.7%). The resazurin dye based quantification of minimum inhibitory concentration of the DARP-7 crude extract was found to be 41.34 µg and 46.44 µg against S. aureus and E.coli , respectively. Further, the compound profiling was done using UV-VIS, FTIR, EEM and GC-MS confirming the presence of polyene conjugates. Thus, the study delivers coastal lichen could be promising source for isolating bioactive metabolites producing rare actinobacteria. Furthermore, the use of a statistical optimization tool to improve bioactive metabolite yield is discussed.

ANTIBACTERIAL EFFICACY OF STREPTOMYCES FRADIAE BUCBTPVD9 FROM MARINE AGAINST CARBAPENEM RESISTANT KLEBSIELLA PNEUMONIA

The emergence of drug resistance is one of the major threats which is now becoming an alarming situation around the world. The UTI causing organisms are also becoming resistant towards the available treatment protocols. Hence the discovery of new, efcient antibacterial metabolites is in need. Actinobacteria has its proven records in the eld of pharmaceutical industry, the secondary metabolites are potent towards the resistant strains. The aim of this study is to identify the antibacterial metabolite producing actinobacterial strains from estuary soil. Study focused on collecting soil samples from estuary in Kerala and Tamil Nadu. From the collected soil samples around nine actinobacterial strains were isolated. Among the nine different strains one strain BUCBT-PVD9 was found to be effective against all the UTI MDR strains which was taken for further study. On characterizing the potent strain it was evident that the strain belongs to Streptomyces fradiae, based on biochemical, spore arrangements and molecular characterization. Further the one factor optimization was performed to check the inuencing factor for enhanced antibacterial metabolite production. Factors like pH, temperature, Nitrogen &amp; Carbon sources along with incubation period on SSY media which showed increased production of metabolite was optimized to increase the yield of the active metabolite. MIC of the ethyl acetate fraction was determined and found to be 31.25 µg/ml against CRKP and 250 µg/ml against ATCC 1705. Further studies are required to characterize the active metabolite which is responsible for the antibacterial activity.

The biliary microbiome in ischaemic-type biliary lesions can be shaped by stenting but is resilient to antibiotic treatment.

This study aims to characterize the biliary microbiome as neglected factor in patients with ischaemic-type biliary lesions (ITBL) after liver transplantation. Therefore, the V1-V2 region of the 16S rRNA gene was sequenced in 175 bile samples. Samples from patients with anastomotic strictures (AS) served as controls. Multivariate analysis and in silico metagenomics were applied cross-sectionally and longitudinally. The microbial community differed significantly between ITBL and AS in terms of alpha and beta diversity. Both, antibiotic treatment and stenting were associated independently with differences in the microbial community structure. In contrast to AS, in ITBL stenting was associated with pronounced differences in the biliary microbiome, whereas no differences associated with antibiotic treatment could be observed in ITBL contrasting the pronounced differences found in AS. Bacterial pathways involved in the production of antibacterial metabolites were increased in ITBL with antibiotic treatment. After liver transplantation, the biliary tract harbours a complex microbial community with significant differences between ITBL and AS. Fundamental changes in the microbial community in ITBL can be achieved with biliary stenting. However, the effect of antibiotic treatment in ITBL was minimal. Therefore, antibiotics should be administered wisely in order to reduce emerging resistance of the biliary microbiome towards external antibiotics.

Bacillibactin class of siderophore antibiotics from a marine symbiotic Bacillus as promising antibacterial agents

Preliminary antibacterial metabolite production screening unveiled thatB. amyloliquefaciens MTCC 12,713 associated with the intertidal red alga Kappaphycus alverezii exhibited potential inhibitory effects against drug-resistant pathogens methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus faecalis, Pseudomonas aeruginosa, and Klebsiella pneumoniae. Four homologous siderophore types of bacillibactins were isolated from a heterotrophic marine bacterium through bioactivity-guided purification. All detectable natural product gene clusters in B. amyloliquefaciens MTCC 12,713 were analyzed by sequencing the complete genome of the bacterium. The studied compounds displayed broad spectrum bactericidal activity against multidrug-resistant strains with a range of minimum inhibitory concentration values from 1.56 to 6.25µg/mL, whereas standard antibiotic chloramphenicol was active at 6.25 to 12.5µg/mL. Structure-bioactivity relationship assessment showed that higher electronic values were responsible for antibacterial properties against the nosocomial pathogens. The 2, 3-dihydroxybenzoate (dhb)-assisted biosynthetic pathway of catecholate-enclosed bacillibactins was proposed through the bacillibactin synthase multienzyme complex catalysis followed by dimerization of dhbACEBF operons with 16 genes (~ 12kb bacterial genome). The present findings recognized an undescribed 4-methoxy-11'-pentanoyloxy-bacillibactin C as a source of potential antibacterial agent for use against drug-resistant pathogens for pharmaceutical applications. KEY POINTS: • Bacillus amyloliquefaciens in association with Kappaphycus alverezii was isolated • Four antibacterial bacillibactin analogs were identified from symbiotic bacterium • 4-Methoxy-11'-pentanoyloxy-bacillibactin C showed potential antibacterial activity.

Optimization of cultural conditions affecting improved bioactive metabolite production by endophytic fungus Trichoderma harzianum

The present study aimed to optimize cultural conditions for optimum bioactive metabolite production by endophytic fungus Trichoderma harzianum, isolated by surface sterilization method from the leaf of the eucalyptus plant. The fungus was identified based on morphological characterization. Fungal metabolites were carried out by ethyl acetate solvent. The antibacterial activity was tested against Escherichia coli (ATCC 25922) and Staphylococcus aureus (NCTC 6571). Various carbon, nitrogen sources, pH, temperature, incubation period, and NaCl on the antibacterial metabolite production were studied. Bioactive metabolite production of T. harzianum exhibits a broad spectrum of in vitro antibacterial activity against two strains of bacteria. For the optimum production of bioactive metabolites, Dextrose and Glucose were found to be the best sources of carbon and the best sources of Nitrogen Yeast extract (YE) and (NH4)2SO. The maximum production of bioactive metabolites occurs at pH 7 and 25°C.; the NaCl showed a positive influence on bioactive metabolites.

Pectobacterium parvum sp. nov., having a Salmonella SPI-1-like Type III secretion system and low virulence.

Pectobacterium strains isolated from potato stems in Finland, Poland and the Netherlands were subjected to polyphasic analyses to characterize their genomic and phenotypic features. Phylogenetic analysis based on 382 core proteins showed that the isolates clustered closest to Pectobacterium polaris but could be divided into two clades. Average nucleotide identity (ANI) analysis revealed that the isolates in one of the clades included the P. polaris type strain, whereas the second clade was at the border of the species P. polaris with a 96 % ANI value. In silico genome-to-genome comparisons between the isolates revealed values below 70%, patristic distances based on 1294 core proteins were at the level observed between closely related Pectobacterium species, and the two groups of bacteria differed in genome size, G+C content and results of amplified fragment length polymorphism and Biolog analyses. Comparisons between the genomes revealed that the isolates of the atypical group contained SPI-1-type Type III secretion island and genes coding for proteins known for toxic effects on nematodes or insects, and lacked many genes coding for previously characterized virulence determinants affecting rotting of plant tissue by soft rot bacteria. Furthermore, the atypical isolates could be differentiated from P. polaris by their low virulence, production of antibacterial metabolites and a citrate-negative phenotype. Based on the results of a polyphasic approach including genome-to-genome comparisons, biochemical and virulence assays, presented in this report, we propose delineation of the atypical isolates as a novel species Pectobacterium parvum, for which the isolate s0421T (CFBP 8630T=LMG 30828T) is suggested as a type strain.

Optimization of fermentation conditions through response surface methodology for enhanced antibacterial metabolite production by Streptomyces sp. 1-14 from cassava rhizosphere.

Streptomyces species 1–14 isolated from cassava rhizosphere soil were evaluated for their antibacterial efficacy against Fusarium oxysporum f.sp. cubense race 4 (FOC4). Of the 63 strains tested, thirteen exhibited potent antibacterial properties and were further screened against eight fungal pathogens. The strain that showed maximum inhibition against all of the test pathogens was identified by 16S rDNA sequencing as Streptomyces sp. 1–14, was selected for further studies. Through the propagation of Streptomyces sp. 1–14 in soil under simulated conditions, we found that FOC4 did not significantly influence the multiplication and survival of Streptomyces sp. 1–14, while indigenous microorganisms in the soil did significantly influence Streptomyces sp. 1–14 populations. To achieve maximum metabolite production, the growth of Streptomyces 1–14 was optimized through response surface methodology employing Plackett-Burman design, path of steepest ascent determinations and Box-Behnken design. The final optimized fermentation conditions (g/L) included: glucose, 38.877; CaCl2•2H2O, 0.161; temperature, 29.97°C; and inoculation amount, 8.93%. This optimization resulted in an antibacterial activity of 56.13% against FOC4, which was 12.33% higher than that before optimization (43.80%). The results obtained using response surface methodology to optimize the fermentation medium had a significant effect on the production of bioactive metabolites by Streptomyces sp. 1–14. Moreover, during fermentation and storage, pH, light, storage temperature, etc., must be closely monitored to reduce the formation of fermentation products with reduced antibacterial activity. This method is useful for further investigations of the production of anti-FOC4 substances, and could be used to develop bio-control agents to suppress or control banana fusarium wilt.

Inoculum type affect the efficacy of the endophytic Bacillus amyloliquefaciens subsp. plantarum strain 32a against the plant pathogen Agrobacterium tumefaciens

Several factors may affect the success of biocontrol agents in the field, some of which are sparsely studied. This work aimed to evaluate the influence of the inoculum type of Bacillus amyloliquefaciens subsp. plantarum 32a on the production of antibacterial metabolites, the colonization level of tomato and the control efficacy of crown gall disease. When 32a cells were grown in the optimized medium, spore inoculum yielded approximately 10 fold more anti-Agrobacterium activity than vegetative inoculum. LC-MS analysis showed that spore inoculated culture produced a pronounced shift toward shorter alkyl chains for surfactins (C13 and C14). When applied to the soil, 32a successfully colonized roots, stem and leaves of tomato. Higher population density was obtained during the treatment of soil with spores, compared to that with vegetative cells. The crown gall disease symptoms, caused by A. tumefaciens, were reduced by strain 32a at different extent depending on the inoculum type treatment. A more pronounced protection was obtained when 32a spores were used for soil inoculation.In this study, we showed for the first time that the inoculum type is one of the important factors affecting the success of a biocontrol agent. This information has significant implications in improving the efficacy of biopesticides.

OPTIMIZATION PRODUCTION CONDITIONS OF ANTIBACTERIAL METABOLITE FROM STREPTOMYCES SP.

Objectives: The paper aimed to isolate Streptomyces strain having the ability to produce antibacterial metabolites and optimize some environmental parameters for excellent antibiotic production.Methods: Different soil samples were collected from extreme environments of desert regions at Karbala Province, Iraq. Actinomycetes were isolated using different media. The primary screening for antibacterial production was accomplished, and the antibacterial activities were tested against pathogenic bacteria, including Escherichia coli, Staphylococcus aureus, Streptococcus agalactiae, and Pseudomonas aeruginosa. The most potent strain was chosen for optimizing some of environmental parameters to increase the bioactive metabolite production. Different parameters were studied such as culture media, temperature, pH, and agitation rate.Results: About eight Streptomyces strains were isolated from soil samples. All isolates appeared variable levels of antibiotic productions against Gram-positive and negative pathogenic bacteria, and the best one was Streptomyces sp. LHR 9. The antibacterial metabolite production from Streptomyces sp. LHR 9 was affected by various cultural parameters. Glucose soybean meal broth as a fermentation medium at pH 7 yielded the highest antibiotic production under the optimal fermentation conditions, including the temperature at 35°C with 200 rpm (revolution/min) agitation rate and 7 days incubation period.Conclusion: The Streptomyces sp. LHR 9 showed antibacterial activity against both Gram-positive and negative pathogenic bacteria. It may consider as a potential source of drug production. Further study needs to purification and characterization of antibiotic and analyzes the mechanism for the antimicrobial activity of this bioactive compound.

OPTIMIZATION OF MEDIUM COMPOSITION FOR ANTIBACTERIAL METABOLITE PRODUCTION FROM STREPTOMYCES SP.

Objectives: This paper aimed to optimize some essential nutritional components (carbon, nitrogen, and phosphate) of fermentation medium necessary for the production of antibacterial metabolites from Streptomyces sp.Materials and Methods: Streptomyces sp. LH9 previously isolated from desert soil in Karbala Province, Iraq. This strain produced antibiotic against 4 pathogenic bacteria, including Escherichia coli, Staphylococcus aureus, Streptococcus agalagtiae, and Pseudomonas aeruginosa. For optimizing, the essential nutritional requirements such as carbon, nitrogen, and phosphate in fermentation media different concentrations of these sources were used to improve the antibacterial metabolite production.Results: All the studied nutritional parameters were had impacts on the antibacterial metabolite production from Streptomyces sp. LH9. The actinobacterial strain produced a highest antibiotic metabolites when was grown in the fermentation medium supplemented with 2% dextrose (as a sole carbon source), 0.05% peptone (as a sole nitrogen source), and 0.05% K2HPO4 at pH 7 and incubated under optimal conditions; at 30°C with 250 rpm (revolutions/min) agitation for 7 days.Conclusion: Streptomyces sp. LH9 was a good producer for antibacterial against Gram-positive and Gram-negative bacteria, which required simple nutritional supplements in the fermentation medium. Furthermore, could be utilized the industrial waste for improving the production in the most economic manner.

Enhanced antibacterial metabolite production through the application of statistical methodologies by a Streptomyces nogalater NIIST A30 isolated from Western Ghats forest soil.

Streptomyces strains isolated from Nelliyampathy forest soil of Western Ghats, Kerala, India were evaluated for their antibacterial efficacy against two indicator pathogenic bacteria (Escherichia coli and Staphylococcus aureus). Among 140 strains tested, sixteen recorded potent antibacterial properties and were further screened against eleven bacterial pathogens. A strain identified as Streptomyces nogalater and designated as NIIST A30 exhibited maximum inhibition against all the test pathogens. Among the eight fermentation media tested, inorganic salts starch broth recorded the best for antibacterial production. The ethyl acetate crude extract exhibited antioxidant properties with IC50 value of 30 μg/mL and had no cytotoxicity towards L6, H9c2 and RAW 264.7 cell lines up to a concentration of 50 μg/mL. Maximum metabolite production was achieved in pH 7.0 at 35°C after 7 days incubation. The significant media components for maximum metabolite production were optimized through response surface methodology employing Plackett-Burman and Box-Behnken designs. The composition of the final optimized medium was soluble starch, 14.97g; (NH4)2SO4, 2.89g; K2HPO4, 2.07g; MgSO4.7H2O, 1g; NaCl, 1g, CaCO3, 2g; FeSO4.7H2O, 1mg; MnCl2.7H2O, 1mg; and ZnSO4.7H2O, 1mg per litre of distilled water. The optimization resulted an antibacterial activity of 28±1.5mm against S. epidermidis which was in close accordance with the predicted value of 30 mm. It is also evident from the result that an increase of 86.66% antibacterial production was recorded in optimized media. The chosen method was economical, efficient and useful for future antibacterial drug discovery from a broad spectrum metabolite producer like Streptomyces nogalater NIIST A30.

Production and characterization of a new antibacterial peptide obtained from Aeribacillus pallidus SAT4

A novel thermophilic bacterial strain of the genus Aeribacillus was isolated from Thar Dessert Pakistan. This strain showed significant antibacterial activity against Micrococcus luteus, Staphylococcus aureus, and Pseudomonasaeruginosa. The strain coded as ‘SAT4’ resembled with Aeribacillus pallidus in the morphological, biochemical and molecular tests. The production of antibacterial metabolites by SAT4 was optimized. These active metabolites were precipitated by 50% ammonium sulphate and purified through sephadex G-75 gel permeation chromatography and reverse phase HPLC. The molecular weight of 37kDa was examined by SDS-PAGE. The structural elucidation of the purified product was studied by FTIR, 1H and 13C NMR. The X-ray diffractions study showed that the crystals belonged to the primitive orthorhombic lattice (a=12.137, b=13.421, c=14.097Å) and 3D structure (proposed name: Aeritracin) was determined. This new peptide antibacterial molecule can get a position in pharmaceutical and biotechnological industrial research.

Optimization of Cultural Conditions for Production of Antibacterial Metabolites from &lt;i&gt;Streptomyces coelicoflavus&lt;/i&gt; BC 01

The aim of the present study was to optimize various cultural conditions for the production of antibacterial metabolites by Streptomyces coelicoflavus BC 01 isolated from mangrove soil, Visakhapatnam, Andhra Pradesh, India. The effect of various factors such as carbon and nitrogen sources, different concentrations of NaCl and K2HPO4, different temperature, pH, incubation time and agitation on antibacterial metabolites production were studied. The production of antibacterial metabolites by the isolate Streptomyces coelicoflavus BC 01 was greatly influenced by the cultural conditions. Glucose (1.2%) and soya bean meal (1%) seemed to be the best carbon and nitrogen source respectively, followed by NaCl (1%) and K2HPO4 (0.25%). Maximum production of antibacterial metabolites was observed at a temperature of 30 °C, with pH 7.2, at 160 rpm for 96 hrs. These optimized parameters can be further useful to design a fermentation medium to achieve maximum yield of antibacterial metabolites from Streptomyces coelicoflavus BC 01.