Producing Bacillus Sp Research Articles

Selection and Molecular Response of AHL-lactonase (aiiA) Producing Bacillus sp. Under Penicillin G-induced Conditions.

Quorum sensing (QS) is the process by which microorganisms employ chemicals called autoinducers (AIs) to communicate with their population. The QS mechanism generally controls the expression of the virulence related genes in bacteria. N-acyl homoserine lactones (AHLs) are the most widespread QS molecules. Due to their diverse AHL-lactonase activities, Bacillus species make particularly suitable candidates for procedures such as demolition of pathogenic bacterial QS signals and bioremediation of β-lactam antibiotics from contaminated environments. In this study, seven Bacillus strains with Quorum quenching (QQ) activity were isolated using an enrichment medium supplemented with Penicillin G (PenG). The AHL-lactonase encoding gene (aiiA) was amplified by PCR and sequenced. Amino acid sequences underwent multiple sequence alignment. Docking studies were carried out with both C6HSL and PenG ligand using AutoDock tools. The aiiA amino acid sequences of the isolates were found to be well conserved. Furthermore, amino acid sequence alignment revealed that 74.9% of amino acid sequences were conserved in the genus Bacillus. Docking of the C6HSL to wild type (3DHA) and H97D variant reduced the docking score by only 0.1kcal/mol for the mutated protein. When PenG docked with a higher (1.5kcal/mol) score as a ligand to wild-type and mutant receptors, the docking score for the mutated protein likewise decreased by 0.1kcal/mol. This research contributed to the diversification of organisms with QQ activity and beta-lactam antibiotic resistance. It also clarified the binding score of the PenG ligand to the Bacillus AHL lactonase molecule for the first time.

Diversity and Distribution of Potential Biosurfactant Producing Bacillus Sp MN 243657, GC-MS Analysis and its Antimicrobial Study

Biosurfactants are microbially produced surface-active compounds. They are amphiphilic molecules with hydrophilic and hydrophobic regions. The demand for biosurfactants has been exponentially growing as they are nontoxic and biodegradable. They have different applications in several industrial sectors. The objective of this study was to isolate and characterize the native bacteria which produce biosurfactants from oil contaminated soil of different places in Kerala and Tamil Nadu, India. The soil samples were collected from petrol pumps and workshops where the soil is contaminated with petrol, diesel and oil. The bacteria were isolated from contaminated soil samples and confirmed as Bacillus sp.The cultures were screened for biosurfactant production by different screening techniques such as blood hemolysis, oil spreading assay, emulsification ability assay, bacterial adherence to hydrocarbons activity. The potential biosurfactant producing culture was selected and identified using molecular techniques and submitted to NCBI Gene Bank (MN 243657 – Bacillus sp). The selected bacterial culture was used for biosurfactant production and these were characterized by UV, TLC, FTIR and GC -MS analysis. The derived biosurfactant's Rf value was 0.68 as determined by a TLC chromatogram. In a UV-visible spectroscopy study, the isolated biosurfactant displayed a highest peak at 415 nm. According to FTIR analysis, the isolated biosurfactant displayed an intense peak at 3340 cm -1. The large peaks of the biosurfactant were observed at various retention times of 12.75, 10.22, 4.98, and 3.87, respectively, after GC-MS analysis. Antibacterial and antifungal activity of the biosurfactant was identified against pathogenic bacteria such as P.aeruginosa, E. coli, K. pneumoniae, S. aureus and fungi Aspergillus niger, Aspergillus terreus, Aspergillus flavus.

Optimization of Biomass of Keratinase Producing Bacillus sp CBNRBT2 to Utilize in Whole-Cell Immobilization for Feather Degradation

Bacillus sp CBNRBT2, obtained from Centre for Bioscience and Nanoscience Research, was used in this study. Initially, biomass was optimized for the incubation period, pH, and temperature, following biomass optimization with RSM. The obtained organism was able to produce keratinase, which was found to be a 64 KDa protein. Now the biomass produced using the optimized condition was immobilized and checked for its ability to degrade keratinase. Efficiency was compared with the whole organism. Immobilized organisms were degrading keratin and feather better. It was found to reduce featherweight by 41 %. Thus, this immobilized bacterium can be used for poultry waste treatment.

Isolation of an acid producing Bacillus sp. EEEL02: Potential for bauxite residue neutralization

Bauxite residue deposit area (BRDA) is a typical abandoned mining wasteland representing extreme hostile environment with increased alkalinity. Microbially-driven neutralization of bauxite residue, based on the microbial acid producing metabolisms, is a novel strategy for achieving rapid pH neutralization and thus improving its environmental outcomes. The hypothesis was that these extreme conditions promote microbial communities which are capable of novel ecologically relevant functions. Several alkaliphilic acid producing bacteria were isolated in this study. One strain was selected for its superior growth pattern and acid metabolism (termed EEEL02). Based on the phylogenetic analysis, this strain was identified as Bacillus thuringiensis. The optimized fermentation conditions were as follows: pH 10; NaCl concentration 5%; temperature 25 °C; EEEL02 preferred glucose and peptone as carbon and nitrogen sources, respectively. Based on optimal fermentation conditions, EEEL02 induced a significant pH reduction from 10.26 to 5.62 in 5-day incubation test. Acetic acid, propionic acid and CO2 (g) were the major acid metabolites of fermentation, suggesting that the pH reduction in bauxite residue may be caused by acid neutralization derived from microbial metabolism. This finding provided the basis of a novel strategy for achieving rapid pH neutralization of bauxite residue.

Isolation and characterization of a newly keratinase producing Bacillus sp N1 from tofu liquid waste

Keratinase is one of important industrial enzyme. The enzyme is produced by wide range of microbes. Microbial diversity offers keratinase diversity as well. Tofu liquid waste is rich with protein and a good natural environment for microorganism which produced extracellular protein hydrolases. This work reports our work on an isolation of a newly keratinase producing bacterium from tofu liquid waste. A keratinase producing bacterium was isolated in four steps: microbial enrichment using chicken feather to elevate population of keratinase producing microorganism, selection of protease producing microorganism by growing it on skim-milk agar medium following by securing colonies with proteolitic index above 3, selection of keratinase producing microorganism in chicken feather liquid medium, and selection of keratinase producing microorganism with highest keratinase activity. Species of a selected microorganism was identified base on 16S rRNA gene sequence. the isolate was identified as Bacillus sp with maximum sequence identity of 89% compare to the available sequence on the data base. Bacillus sp is capable to produce extracellular keratinase under 1% feather keratin substrate. Furthermore characterization showed that the enzyme exhibits potential ability to dehair goat skin with better dehaired surface profile.

Heterologous expression of β-γ-type cyclodextrin glycosyltransferase of newly isolated alkaliphilicBacillussp. SD5 inPichia pastoris

Cyclodextrin glycosyltransferase (CGTase) enzyme is used industrially to obtain cyclodextrins. In this study, a newly isolated alkaliphilic CGTase producing Bacillus sp. SD5 was used as the source organism for the gene encoding for CGTase. The gene was amplified and sequenced in preparation for cloning into Pichia pastoris for methanol-induced expression and extracellular secretion. Three strategies were employed in designing the amplification primers for obtaining the fragments to be used in transformation. Hence, three P. pastoris X33 clones were obtained: N2 (with natural gene sequence), S3 (also encoding the c-myc epitope and polyhistidine tail), and M5 (encoding the polyhistidine tail). Extracellular CGTase activity was monitored throughout fermentation for each clone. The molecular weights of the enzymes were in the range of 85–90 kDa and all three clones showed maximum CGTase activity upon 24 h of induced fermentation. The CGTase enzyme obtained from the M5 clone had Km and Vmax values 13.59 mg/mL and 1153 µmol/(mg min), respectively. The enzyme was purified and displayed optimum activity at 50°C and pH 6 and pH 9. HPLC analysis of reaction products following 10 min of incubation in a reaction solution containing 4% starch showed 852.5 mg/L β-cyclodextrin and 89.6 mg/L γ-cyclodextrin being produced.

Heterologous expression of β-γ-type cyclodextrin glycosyltransferase of newly isolated alkaliphilic Bacillus sp. SD5 in Pichia pastoris

Cyclodextrin glycosyltransferase (CGTase) enzyme is used industrially to obtain cyclodextrins. In this study, a newly isolated alkaliphilic CGTase producing Bacillus sp. SD5 was used as the source organism for the gene encoding for CGTase. The gene was amplified and sequenced in preparation for cloning into P. pastoris for methanol induced expression and extracellular secretion. Three strategies were employed in designing the amplification primers for obtaining the fragments to be used in transformation. Hence three Pichia pastoris X33 clones were obtained; N2 (with natural gene sequence), S3 (also encoding the c-myc epitope and polyhistidine tail) and M5 (encoding the polyhistidine tail). Extracellular CGTase activity was monitored throughout fermentation for each clone. The molecular weights of the enzymes were in the range of 85-90 kDa and all three clones showed maximum CGTase activity upon 24 hours of induced fermentation. The CGTase enzyme obtained from the M5 clone had Km and Vmax values 13.59 mg/mL and 1153 μmol/(mg.min), respectively. The enzyme was purified and displayed optimum activity at 50 °C and pH 6 and pH 9. HPLC analysis of reaction products following 10 minutes of incubation in a reaction solution containing 4% starch showed 852.5 mg/L β-cyclodextrin and 89.6 mg/L γ-cyclodextrin being produced.

Inoculation of 1-aminocyclopropane-1-carboxylate deaminase–producing bacteria along with biosurfactant application enhances the phytoremediation efficiency of Medicago sativa in hydrocarbon-contaminated soils

ABSTRACTPhytoremediation efficiency of Alfa alfa (Medicago sativa) was evaluated in hydrocarbon-contaminated soil with the combined application of 1-aminocyclopropane-1-carboxylate (ACC) deaminase–producing Bacillus sp. PVMX4 and an isolated biosurfactant from this strain. Results on the plant growth–promoting (PGP) traits of Bacillus sp. PVMX4 revealed that phosphate (P) solubilization, indole-3-acetic acid (IAA) production, and ACC deaminase activity were not affected by low-concentration hydrocarbon amendment in the form of crude oil. Bacillus sp. PVMX4 was able to utilize crude oil as a sole carbon source in mineral salt medium (MSM), and this strain synthesized significant quantities of biosurfactant in growth medium quantified by an emulsification index of 69.2 EI24% and surface tension reduction of 26.2 mN/m at the end of the experimental period. Biosurfactant, when partially purified and characterized by thin-layer chromatography (TLC) and Fourier transform infrared spectroscopy (FT-IR), revealed it to be a lipopeptide-type biosurfactant. Pilot-scale phytoremediation studies conducted under growth chamber conditions in hydrocarbon-contaminated soil using Medicago sativa along with combined application of ACC deaminase–containing bacteria and biosurfactant recorded 76.4% hydrocarbon degradation.

Genomic and functional features of the biosurfactant producing Bacillus sp. AM13

Genomic studies provide deeper insights into secondary metabolites produced by diverse bacterial communities, residing in various environmental niches. This study aims to understand the potential of a biosurfactant producing Bacillus sp. AM13, isolated from soil. An integrated approach of genomic and chemical analysis was employed to characterize the antibacterial lipopeptide produced by the strain AM13. Genome analysis revealed that strain AM13 harbors a nonribosomal peptide synthetase (NRPS) cluster; highly similar with known biosynthetic gene clusters from surfactin family: lichenysin (85%) and surfactin (78%). These findings were substantiated with supplementary experiments of oil displacement assay and surface tension measurements, confirming the biosurfactant production. Further investigation using LCMS approach exhibited similarity of the biomolecule with biosurfactants of the surfactin family. Our consolidated effort of functional genomics provided chemical as well as genetic leads for understanding the biochemical characteristics of the bioactive compound.

A High Salt Stable ɑ-Amylase by Bacillus Sp. MRS6 Isolated from Municipal Solid Waste; Purification, Characterization and Solid State Fermentation

Salt-tolerant alkaline amylase producing Bacillus sp. MRS6 was isolated from three municipal waste disposal site of Medinipur town in the Paschim Medinipur district of southern West Bengal, India. The strain had been characterized from a polyphasic approach. Extracellular enzyme production was carried out in mineral salt media at pH-7, 35°C with 2% soluble starch as sole carbon source. It was found that the amylase, produced by the salttolerant strain possessed high activity in a range of alkaline pH (6-9), with pH-8 as optimum. An incubation period of 30 min at 35°C was found as optimum temperature condition of its activity. This alkaliphilic, salt-tolerant enzyme was found to stay stable upto 80°C, 4M NaCl. Mn2+, Ca2+ plays critical role in >80% increasing of this enzyme activity. EDTA, β-merkeptoethanol and detergents strongly inhibit enzyme activity. This enzyme was able to ferment the solid substrates i.e. wheat bran greater than rice husk. This enzyme was purified partially by cold acetone precipitation and the molecular mass was found to be 55 kDa by SDS PAGE. The present findings suggested the enzyme to be halophilic alkaline amylase. The present enzyme is of great significance in present day biotechnology with applications ranging from food, fermentation, textile, detergent to paper industries.

Production, purification and characterisation of thermostable metallo-protease from newly isolated Bacillus sp. KG5

Background: Due to the importance of microbial proteases in biotechnological applications, a number of microorganisms are being explored. The production, purification and characterisation of extracellular metallo-proteases by producing Bacillus sp. KG5 was studied. Material and Methods: Bacterial strain KG5 was isolated from Kos (Bingol) hot spring. The strain KG5 was identified by morphological, physiological, biochemical and 16S rRNA gene sequencing. The effects of various parameters on protease production, such as time, temperature, pH, carbon and nitrogen sources and CaCU were studied. The enzyme was purified by ammonium sulphate precipitation and Sephadex G-75 gel permeation chromatography. Molecular weight was calculated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and zymographic analysis. The effects of some metal ions, chelators and inhibitors on enzyme activity were determined. Results: The optimum temperature, pH and incubation period for protease production were 40-45°C, 7.0 and 24 h, respectively. It was determined that the best nitrogen sources were yeast extract and urea, while the best carbon sources were lactose and galactose. However, glucose as a source of carbon was found to inhibit the production of the enzyme. The maximum enzyme production was increased in the presence of CaCU. The molecular weight of purified enzyme was found to be approximately 48 kDa. It was found that the enzyme was fully stable in the presence of 2 mM CaCU at 50°C after 120 min. Purified protease was significantly activated by Ca2 + and Mg2 + , while it was greatly inhibited by Cu2 + , Zn2 + , Hg2 + and SDS as well as by the metal ion chelators ethylenediaminetetraacetic (EDTA) and 1,10-phenanthroline. Phenylmethylsulfonyl fluoride (PMSF) had a little effect on the enzyme. Conclusions: Our findings suggest the potential of this isolate for protease production and that this enzyme may be suitable for biotechnological applications.

Production of extracellular alkaline protease by new halotolerant alkaliphilic Bacillus sp. NPST-AK15 isolated from hyper saline soda lakes

Alkaline proteases are among the most important classes of industrial hydrolytic enzymes. The industrial demand for alkaline proteases with favorable properties continues to enhance the search for new enzymes. The present study focused on isolation of new alkaline producing alkaliphilic bacteria from hyper saline soda lakes and optimization of the enzyme production. A new potent alkaline protease producing halotolerant alkaliphilic isolate NPST-AK15 was isolated from hyper saline soda lakes, which affiliated to Bacillus sp. based on 16S rRNA gene analysis. Organic nitrogen supported enzyme production showing maximum yield using yeast extract, and as a carbon source, fructose gave maximum protease production. NPST-AK15 can grow over a broad range of NaCl concentrations (0–20%), showing maximal growth and enzyme production at 0–5%, indicated the halotolerant nature of this bacterium. Ba and Ca enhanced enzyme production by 1.6 and 1.3 fold respectively. The optimum temperature and pH for both enzyme production and cell growth were at 40°C and pH 11, respectively. Alkaline protease secretion was coherent with the growth pattern, started at beginning of the exponential phase and reached maximal in mid stationary phase (36 h). A new halotolerant alkaliphilic alkaline protease producing Bacillus sp. NPST-AK15 was isolated from soda lakes. Optimization of various fermentation parameters resulted in an increase of enzyme yield by 22.8 fold, indicating the significance of optimization of the fermentation parameters to obtain commercial yield of the enzyme. NPST-AK15 and its extracellular alkaline protease with salt tolerance signify their potential applicability in the laundry industry and other applications.

English

Microbial proteases are vastly demanded industrial enzyme with broad commercial application in various sectors. Naturally, the bacterial strains are well known for their ability to excrete enzymes into the environment. The current work was undertaken to isolate and characterize an effective extracellular alkaline protease producing Bacillus sp. A total of twenty nine bacterial strains were isolated from coastal regions of rhizosphere soil around the Cuddalore District Tamil Nadu, India. Out of twenty nine isolates, seven strains namely, IAS01, IAS02, IAS03, IAS04, IAS05, IAS06 and IAS07 show 45% clearance of hydrolyzing zone on skim milk agar plate. The positive isolates were further assay on small scale laboratory fermentation media for their protease productivity when compared with standard culture, Bacillus subtilis (MTCC-1789). As a result, the highest enzyme productivity that appeared in the strain IAS01 was found to be 332.13±1.31 U/ml at alkaline condition. Therefore, the selected isolate IAS01 was a promising strain for alkaline protease producer and identified as B. subtilis based on its morphological, physiological, biochemical characters and analysis of the 16S rRNA gene sequencing study. The partial 16S rRNA sequence was submitted to Genbank, with the accession number KF761633. Key words: Bacillus subtilis, alkaline protease production, SPSS statistic analysis.

English

A protease producing Bacillus sp. GA CAS10 was isolated from ascidian Phallusia arabica , Tuticorin, Southeast coast of India. Response surface methodology was employed for the optimization of different nutritional and physical factors for the production of protease. Plackett-Burman method was applied to identify important factors (anchovy waste, KH 2 PO 4 , NaCl and temperature) influencing protease production. Further optimization was done by response surface methodology using central composite design. Under the optimized conditions by central composite design, the protease experimental yield (842.102 U/ml) closely matched the predicted yield by the statistical model (830.307 U/ml) with R 2 = 99.94%. The time course of protease production was increased using the RSM optimized medium (856.29 U/ml) (anchovy waste 20.50 g/l, KH 2 PO 4 3.06 g/l, NaCl 42.91 g/l, temperature 43.36°C, 42 h and pH 9) compared with the un-optimized basal medium (267.33 U/ml). The improvement of protease production by microbial conversion of anchovy waste suggested its potential utilization to generate high value added products using cheap carbon and nitrogen substrates. Keywords: Protease, anchovy waste, statistical optimization, ascidian associated bacteria. African Journal of Biotechnology Vol 13(27) 2741-2749

SCREENING AND MOLECULAR CHARACTERIZATION OF BACILLUS SP PR01 FOR THE PRODUCTION OF PROTEASE ENZYME

The current study was attempted to isolate and characterize the protease producing Bacillus sp. Among the 3 strains isolated from soil sample collected f rom kuppam region, Chennai, India. One strain (PR01) exhibited potent proteolytic activity. Based on the morphological, biochemical and molecular characterization, the isolate (PR01) was identified as Bacillus sp. The strain was designated as Bacillus sp P R01. The maximum growth of Bacillus sp PR01was observed at pH 7. The optimum temperature for the growth of Bacillus sp PR01 was found to be 27 ° C an d incubation time for 2 days. The maximum growth was noted when yeast extract was used as a nitrogen source a nd dextrose was used as the carbon source. The production of enzyme Bacillus sp PR01 was carried out in production medium. The t otal protein concentration was determined and the specific activity was also performed by casein hydrolysis assay.

Optimization of Fermentation Medium for Producing α-Hydroxyphenylacetic Acid by Using Plackett-Burman Design and Response Surface Methodology

Plackett-Burman design and response surface methodology were applied in order to optimize the fermentation medium of (R)-α-hydroxyphenylacetic acid ((R)-HPA) producing Bacillus sp. HZG-19. The factors playing important roles in the production of (R)-HPA were selected based on Plackett-Burman design. The path of steepest ascent was undertaken to optimize said fermentation medium. Finally, the optimal levels of the factors with the greatest change in regard to product yield were further optimized using Box-Behnken and response surface analysis. The optimal conditions were found to be as follows: casein peptone 30.49 (g × L-1), glycerol 14.09 (g × L-1), KH2PO4 0.1345 (g × L-1), K2HPO4 0.01 (g × L-1), CaCl2 0.1 (g × L-1), MnSO4 0.01 (g × L-1). Under the optimal conditions described above, the yield of (R)-HPA reached 63.30%, which indicated an increase of 14.9%, as compared to the yield obtained before optimization.

Isolation and characterization of polyhydroxyalkanoate and exopolysaccharide producing Bacillus sp. PS1 isolated from sugarcane field in Bhilai, India

Polyhydroxyalkanoates (PHA) and exopolysaccharide (EPS) are important biopolymers. Bacteria produce poly- hydroxyalkanoate by fermenting sugar and lipids as a mechanism of storing carbon and energy under unbalanced growth condition. A bacterium of Bacillus group was isolated from sugarcane field in Bhilai which produced PHA and EPS. It was aerobic, Gram positive, rod shaped, endospore forming and catalase producing bacterium. It was able to grow up to 14% NaCl concentration, pH range from 3 to 10 and temperature range from 27°C to 70°C. Maximum yield of PHA was 38.5 mg/ml at 40°C while at 60°C yield was 34.5 mg/ml. Likewise maximum yield of EPS was 18.5 mg/ml at 37°C. The bacterium has other biotechnological aspects also which is evident from the fact that it has catalase activity up to 65°C and produces urease.

호염성균 유래 45 kDa 혈전용해효소의 순수분리와 생화학적 특성

혈전용해효소를 생산하는 Bacillus sp. J-19가 보편적인 한국의 조미제인 멸치젓갈에서 분리되었다. 그 혈전용해 효소는 에탄올 침전, Sephadex G-50을 이용한 젤 여과법 등을 포함하는 일련의 크로마토그래피 방법으로 순수분리 되었다. 조효소 추출액과 비교해서, 그 효소의 비활성은 1021배 증가하였고, 수율은 23%이었다. 순수분리한 효소의 분자량은 SDS-PAGE 상 약 45 kDa이었다. 특히, 합성기질인 serine protease (H-D-Ile-Pro-Arg-pNA,S-2288)에 대한 아미드활성은 약 17 U/mg이었다. 또한, 그 45 kDa 혈전용해효소의 60% 이상의 활성이 30%(w/v) sodium chloride 의 존재 하에서도 유지되었다. 이러한 발견들은 특이한 혈전용해효소를 제공해서, 실용적인 혈전용해제 개발을 유도할 수 있다. A fibrinolytic enzyme producing Bacillus sp. J-19 was isolated from the popular Korean seasoning, pickled anchovy. The fibrinolytic enzyme was purified to homogeneity by chromatographic methods including ethanol precipitation and gel-filtration using Sephadex G-50. Compared to the crude enzyme extract, the specific activity of the enzyme increased 1021-fold with a recovery of 23%. The purified enzyme was estimated to be approximately 45 kDa by SDS-PAGE. Especially, the amidolytic activity in the presence of the synthetic substrate for serine protease (H-D-Ile-Pro-Arg-pNA, S-2288) represented approximately 17 U/mg. In addition, more than the 60% activity of the 45 kDa fibrinolytic activity was maintained in the presence of up to 30% (w/v) sodium chloride. These findings could provide a unique fibrinolytic enzyme, leading to a potential thrombolytic agent.

Highly thermostable, thermophilic, alkaline, SDS and chelator resistant amylase from a thermophilic Bacillus sp. isolate A3-15

A thermostable alkaline α-amylase producing Bacillus sp. A3-15 was isolated from compost samples. There was a slight variation in amylase synthesis within the pH range 6.0 and 12.0 with an optimum pH of 8.5 (8 mm zone diameter in agar medium) on starch agar medium. Analyses of the enzyme for molecular mass and amylolytic activity were carried out by starch SDS–PAGE electrophoresis, which revealed two independent bands (86,000 and 60,500 Da). Enzyme synthesis occurred at temperatures between 25 and 65 °C with an optimum of 60 °C on petri dishes. The partial purification enzyme showed optimum activity at pH 11.0 and 70 °C. The enzyme was highly active (95%) in alkaline range of pH (10.0–11.5), and it was almost completely active up to 100 °C with 96% of the original activity remaining after heat treatment at 100 °C for 30 min. Enzyme activity was enhanced in the presence of 5 mM CaCl 2 (130%) and inhibition with 5 mM by ZnCl 2, NaCl, Na–sulphide, EDTA, PMSF (3 mM), Urea (8 M) and SDS (1%) was obtained 18%, 20%, 36%, 5%, 10%, 80% and 18%, respectively. The enzyme was stable approximately 70% at pH 10.0–11.0 and 60 °C for 24 h. So our result showed that the enzyme was both, highly thermostable-alkaline, thermophile and chelator resistant. The A3-15 amylase enzyme may be suitable in liquefaction of starch in high temperature, in detergent and textile industries and in other industrial applications.

A highly thermostable and alkaline amylase from a Bacillus sp. PN5

A highly thermostable alkaline amylase producing Bacillus sp. PN5 was isolated from soil, which yielded 65.23 U mL −1 of amylase in medium containing (%) 0.6 starch, 0.5 peptone and 0.3 yeast extract at 60 °C, pH 7.0 after 60 h of incubation. Maximum amylase activity was at pH 10.0 and 90 °C. The enzyme retained 80% activity after 1 h at pH 10.0. It exhibited 65% activity at 105 °C and had 100% stability in the temperature range between 80 and 100 °C for 1 h. In addition, there was 86.36% stability after 1-h incubation with sodium dodecylsulphate. These properties indicated possible use of this amylase in starch saccharification and detergent formulation.