Paddy Husk as Support for Solid State Fermentation to Produce Xylanase from Bacillus pumilus

To optimize culture conditions for xylanase production by solid state fermentation （SSF） using Bacillus pumilus, with paddy husk as support, solid medium contained 200 g of paddy husk with 800 mL of liquid fermentation medium [xylan, 20.0 g/L; peptone, 2.0 g/L; yeast extract, 2.5 g/L; K2HPO4, 2.5 g/L; KH2PO4, 1.0 g/L; NaCl, 0.1 g/L; （NH4）2SO4, 2.0 g/L, CaCl2-2H2O, 0.005 g/L; MgCl2.6H2O, 0.005 g/L; and FeCI3, 0.005 g/L] at pH 9.0 was applied. The highest xylanase activity （142.0 ±0.47 U/g DM] was obtained on the 6th day at 30℃ The optimized paddy husk to liquid fermentation medium ratio was 2：9, and the optimized culture temperature was 40℃. When commercial Birchwood xylan was replaced with different concentrations of corncob, xylanase production was maximized （224.2 U/g DM） in the medium with 150 g/L corncob. Xylanase production was increased by sucrose, fructose and arabinose, whereas reduced by glucose, galactose, lactose and amylose. When organic nitrogen sources were replaced with locally available nitrogen sources such as groundnut powder or sesame seedcake powder or coconut seedcake powder or soy meal powder, the highest xylanase production （290.7 U/g DM） was obtained in the medium with soy meal powder and 16.0 g/L of soy meal powder was the optimum （326.5±0.34 U/g DM）. Based on the optimization studies, B. pumilus produced 2.3 times higher xylanase activity. The medium cost was reduced from 2 458.3 to 178.3 SLR/kg and the total activity which could be obtained from 1 kg of the medium was increased from 48 624 to 220 253 Units.

Growth Performance,Physicochemical Properties of Meat of Broiler Chicken’s Supplemented with Bacillus pumilus

This study examined that the efficiency of Bacillus pumilus(BP)on growth performance and meat quality of broiler chickens.A total of day old 240 male broiler chicks were purchased from local hatchery Hyderabad.The chicks were allocated into four groups with six replicates of 10 birds in each replicate.Four diets were prepared for experiment,which included control as basal diet,BP-0.1(CONT+0.1%BP),BP-0.2(CONT+0.2%BP)and AGP(CONT+zinc bacitracin 20 ppm)as antibiotic growth promotor.The results showed that live body weight(LBW),average daily gain was recorded higher(P<0.01)in birds fed diet with BP-0.1 than control and BP-0.2 groups,as well as ADFI also increased in BP-0.1 than control group.BP-0.1 supplementation significantly reduced feed conversion ratio(FCR)than other groups(P<0.01).Both moisture and crude protein(CP)content influenced by supplementation of BP-0.1 than other groups.However,birds fed diet with BP-0.1 had least fat content in breast meat compared with the other groups(P<0.01).In addition,BP-0.1probiotic-fed birds had the lowest(P<0.01)pH,cooking loss(CL)and drip loss(DL)as compared to control,BP-0.2 and AGP groups.The water holding capacity(WHC)were found higher in BP-0.1 as compared to other groups(P<0.01).In conclusion,Bacillus pumilus probiotic supplementation is a promising approach for substitution of antibiotics in broiler diet for enhancement of growth performance and physiochemical properties of meat.

Analysis of the effects of antifungal peptide P-1 from Bacillus pumilus HN-10 on energy metabolism of Trichothecium roseum

This study investigated the antifungal activity and possible mode of action of Bacillus pumilus HN-10 antifungal peptide P-1 against Trichothecium roseum.The results showed that the antifungal peptide P-1 at a concentration of 1.0μg mL^(-1)had strong antifungal activity against T.roseum.P-1 inhibited the tricarboxylic acid cycle(TCA)pathway and the transporter pathway of NADH to coenzyme Q on the electron transport chain.P-1 significantly reduced succinate dehydrogenase(SDH),malate dehydrogenase(MDH),ATPase,mitochondrial complex enzymes I,II and IV enzyme activities on the electron transport chain,and 5'-triphosphate(ATP),5'-diphosphate(ADP),5'-monophosphate(AMP)content,and energy charge(EC);significantly increased 6-phosphofructokinase(PFK)enzyme activity.The release of Ca^(2+)(OD_(680))from the inner mitochondrial membrane and the openness of the mitochondrial permeability transition pore(MPTP)were analysed,and microscopy was performed following staining of mitochondria with JC-1.The results indicated that P-1 significantly increased the release of Ca^(2+) and the openness of MPTP,decreased the mitochondrial membrane potential,and produced green fluorescence;transcriptomics data analysis showed that there were 39 differentially expressed genes(DEGs)related to energy metabolism enzymes.The results verified by qRT-PCR were basically consistent with the transcriptome sequencing results.Thus,P-1 achieved its inhibitory effect mainly by regulating genes related to energy metabolism.

Silver nanoparticles tolerant bacteria from sewage environment

Silver nanoparticle （SNP） is a threat to soil, water and human health. Protection of environment from silver nanoparticles is a major concern. A sewage isolate, Bacillus pumilus treated with SNPs showed similar growth kinetics to that without nanoparticles. A reduction in the amount of exopolysaccharides was observed after SNPs - B. pumilus culture supernatant interaction. The Fourier transform infrared spectroscopy （FT-IR） peaks for the exopolysaccharides extracted from the bacterial culture supernatant and＇the interacted SNPs were almost similar. The exopolysaccharide capping of the SNPs was confirmed by UV-Visible, FT-IR and X-ray diffraction analysis. The study of bacterial exopolysaccharides capped SNPs with E. coli, S. aureus and M. luteus showed less toxicity compared to uncoated SNPs. Our studies suggested that the capping of nanopartieles by bacterially produced exopolysaccharides serve as the probable mechanism of tolerance.