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Fulltext Susceptibility of Bacillus subtilis to Zinc Oxide Nanoparticles Treatment

Djearamane S, Sundaraji A, Eng PT, Liang SXT, Wong LS, Senthilkumar B

Clin Ter, 2023;174(1):61-66.
PMID: 36655646 DOI: 10.7417/CT.2023.2498

AIM: With the characteristics such as low toxicity, high total surface, ability to inhibit the growth of pathogenic microorganisms, zinc oxide nanoparticles (ZnO NPs), as one of the metallic nanoparticles, have been chosen as an antibacterial agent to treat various skin infections. The present study was aimed to determine the antibacterial potential of ZnO NPs on Bacillus subtilis, the Gram-positive bacterium that can cause skin and wound infections.
METHODS: B. subtilis was exposed to 5 to 150 μg/mL of ZnO NPs for 24 h. The parameters employed to evaluate the antimicrobial potential of ZnO NPs were the growth inhibitory effect on B. subtilis, the surface interaction of ZnO NPs on the bacterial cell wall, and also the morphological alterations in B. subtilis induced by ZnO NPs.
RESULTS: The results demonstrated a significant (p <0.05) inhibition of ZnO NPs on B. subtilis growth and it was in a dose-dependent manner for all the tested concentrations of ZnO NPs from 5 to 150 μg/mL at 24 h. Fourier transformed infrared (FTIR) spectrum confirmed the involvement of polysaccharides and polypeptides of bacterial cell wall in surface binding of ZnO NPs on bacteria. The scanning electron microscopy (SEM) was used to visualize the morphological changes, B. subtilis illustrated several surface alterations such as distortion of cell membrane, roughening of cell surface, aggregation and bending of cells, as well as, the cell rupture upon interacting with ZnO NPs for 24 h.
CONCLUSION: The results indicated the potential of ZnO NPs to be used as an antibacterial agent against B. subtilis. The findings of the present study might bring insights to incorporate ZnO NPs as an antibacterial agent in the topical applications against the infections caused by B. subtilis.

Matched MeSH terms: Bacillus subtilis/metabolism
The Evaluation of Different Bacteriocinogenic Bacillus spp. with Activity Against Staphylococcus spp. and Their Beneficial and/or Hazardous Properties

Fugaban JII, Dioso CM, Choi GH, Bucheli JEV, Liong MT, Holzapfel WH, et al.

Probiotics Antimicrob Proteins, 2024 Feb;16(1):35-52.
PMID: 36445687 DOI: 10.1007/s12602-022-10017-7

The aim of this project was to screen for bacteriocinogenic Bacillus strains with activity versus Staphylococcus spp. with future application in formulation of pharmaceutical antimicrobial preparations. Putative bacteriocinogenic strains, isolated and pre-identified as Bacillus spp. were selected for future study and differentiated based on repPCR and identified as Bacillus subtilis for strains ST826CD and ST829CD, Bacillus subtilis subsp. stercoris for strain ST794CD, Bacillus subtilis subsp. spizizenii for strain ST824CD, Bacillus velezensis for strain ST796CD, and Bacillus tequilensis for strain ST790CD. Selected strains were evaluated regarding their safety/virulence, beneficial properties, and potential production of antimicrobials based on biomolecular and physiological approves. Expressed bacteriocins were characterized regarding their proteinaceous nature, stability at different levels of pH, temperatures, and the presence of common chemicals applied in bacterial cultivation and bacteriocin purification. Dynamic of bacterial growth, acidification, and cumulation of produced bacteriocins and some aspects of the bacteriocins mode of action were evaluated. Based on obtained results, isolation and application of expressed antimicrobials can be realistic scenario for treatment of some staphylococcal associated infections. Appropriate biotechnological approaches need to be developed for cost effective production, isolation, and purification of expressed antimicrobials by studied Bacillus strains.

Matched MeSH terms: Bacillus*
One-step analysis of growth kinetics of mesophilic Bacillus cereus in liquid egg yolk during treatment with phospholipase A2: Model development and validation

Ahmad NH, Huang L, Juneja V

Food Res Int, 2024 Jan;176:113786.
PMID: 38163703 DOI: 10.1016/j.foodres.2023.113786

Liquid egg yolk (LEY) is often treated with phospholipase A2 (PLA2) to improve its emulsifying capacity and thermal stability. However, this process may allow certain pathogens to grow. The objective of this study was to evaluate the growth kinetics of mesophilic Bacillus cereus in LEY during PLA2 treatment. Samples, inoculated with B. cereus vegetative cells, were incubated isothermally at different temperatures between 9 and 50 °C to observe the bacterial growth and survival. Under the observation conditions, bacterial growth occurred between 15 and 48 °C, but not at 9 and 50 °C. The growth curves were analyzed using the USDA IPMP-Global Fit, with the no-lag phase model as the primary model in combination with either the cardinal temperatures model (CTM) or the Huang square-root model (HSRM) as the secondary model. While similar maximum growth temperatures (Tmax) were determined (48.4 °C for HSRM and 48.1 °C for CTM), the minimum growth temperature (Tmin) of the HSRM more accurately described the lower limit (9.26 °C), in contrast to 6.51 °C for CTM, suggesting that the combination of the no-lag phase model and HSRM was more suitable to describe the growth of mesophilic B. cereus in LEY. The root mean square error (RMSE) of model validation and development was <0.5 log CFU/g, indicating the combination of the no-lag phase model and HSRM could predict the growth of mesophilic B. cereus in LEY during PLA2 treatment. The results of this study may allow the food industry to choose a suitable temperature for PLA2 treatment of LEY to prevent the growth of mesophilic B. cereus.

Matched MeSH terms: Bacillus cereus*
Antagonistic activities of mosquito larvicidal Bacillus sphaericus (Neide) against some pathogenic bacteria

Seleena P, Lee HL

Indian J Med Res, 1993 Mar;97:83-4.
PMID: 8505080

Mosquitocidal strains of B. sphaericus serotype H-5a5b were shown for the first time to exhibit antagonistic activities against several human pathogens especially Salmonella. These strains of B. sphaericus also exhibited high larval toxicity against several mosquitoes.

Matched MeSH terms: Bacillus/physiology*
Fulltext Rational mutagenesis of cyclodextrin glucanotransferase at the calcium binding regions for enhancement of thermostability

Goh PH, Illias RM, Goh KM

Int J Mol Sci, 2012;13(5):5307-23.
PMID: 22754298 DOI: 10.3390/ijms13055307

Studies related to the engineering of calcium binding sites of CGTase are limited. The calcium binding regions that are known for thermostability function were subjected to site-directed mutagenesis in this study. The starting gene-protein is a variant of CGTase Bacillus sp. G1, reported earlier and denoted as "parent CGTase" herein. Four CGTase variants (S182G, S182E, N132R and N28R) were constructed. The two variants with a mutation at residue 182, located adjacent to the Ca-I site and the active site cleft, possessed an enhanced thermostability characteristic. The activity half-life of variant S182G at 60 °C was increased to 94 min, while the parent CGTase was only 22 min. This improvement may be attributed to the formation of a shorter α-helix and the alleviation of unfavorable steric strains by glycine at the corresponding region. For the variant S182E, an extra ionic interaction at the A/B domain interface increased the half-life to 31 min, yet it reduced CGTase activity. The introduction of an ionic interaction at the Ca-I site via the mutation N132R disrupted CGTase catalytic activity. Conversely, the variant N28R, which has an additional ionic interaction at the Ca-II site, displayed increased cyclization activity. However, thermostability was not affected.

Matched MeSH terms: Bacillus/enzymology*; Bacillus/genetics; Bacillus/chemistry
Production of L2 lipase by Bacillus sp. strain L2: nutritional and physical factors

Shariff FM, Leow TC, Mukred AD, Salleh AB, Basri M, Rahman RN

J Basic Microbiol, 2007 Oct;47(5):406-12.
PMID: 17910105

A thermophilic bacterium, Bacillus sp. strain L2 was isolated from a hot spring in Perak, Malaysia. An extracellular lipase activity was detected through plate and broth assays at 70 degrees C after 28 h of incubation. The L2 lipase production was growth dependent as revealed by a number of factors affecting the secretion of extracelullar lipase. As for nutritional factors, casamino acids, trehalose, Ca(2+) and Tween 60 were found to be more effective for lipase production. The optimum physical condition for L2 lipase production was obtained at 70 degrees C after 28 h of cultivation time, at pH 7.0, 150 rpm of agitation rate and 1% of starting inoculum size. The activity staining of crude L2 lipase revealed a clearing zone at 39 kDa.

Matched MeSH terms: Bacillus/enzymology*; Bacillus/growth & development; Bacillus/isolation & purification
Fulltext Pengenalpastian mikroflora bakteria selain bacillus sp. Dari kolam air panas Bentong, Pahang, Malaysia

Abdul Hamid Abdul Aziz, Nur Fariza Mat Reffin, Mohamed Kamel Abd Ghani, Hing, Hiang Lian, Ahmad Zorin Sahalan

Jurnal Sains Kesihatan Malaysia, 2012;10(2):53-55.
MyJurnal

Suatu kajian mengenai pemencilan dan pengenalpastian mikroflora bakteria dari kolam air panas telah dilakukan di kolam air panas Bentong, Pahang. Kebanyakan bakteria yang dipencil dari kolam air panas adalah dari Bacillus sp. kerana ia mempunyai ciri adaptasi yang membolehkannya hidup di kawasan suhu yang tinggi dengan pembentukan endospora. Objektif kajian adalah untuk mengenal pasti spesies bakteria selain daripada spesies Bacillus sp. yang boleh dipencilkan dari kolam air panas. Tiga buah kolam air panas (A, B dan C) dikenal pasti dengan julat suhunya antara 36°C-52°C dan nilai pH antara 7.88-8.65. Kajian ini telah berjaya memencilkan dua pencilan bakteria kokus Gram positif dan tiga spesies basilus Gram negatif. Spesies Gram positif tersebut adalah dari genus Streptococcus dan Staphylococcus, manakala bagi Gram negatif pula terdapat masalah dalam pengenalpastian dan hanya dikenali sebagai X, XI and XII.

Matched MeSH terms: Bacillus
Fulltext Whole-Genome Sequence and Fosfomycin Resistance of Bacillus sp. Strain G3(2015) Isolated from Seawater off the Coast of Malaysia

Chan XY, Chen JW, Adrian TG, Hong KW, Chang CY, Yin WF, et al.

Genome Announc, 2017 Mar 30;5(13).
PMID: 28360153 DOI: 10.1128/genomeA.00067-17

Bacillus sp. is a Gram-positive bacterium that is commonly found in seawater. In this study, the genome of marine Bacillus sp. strain G3(2015) was sequenced using MiSeq. The fosfomycin resistant gene fosB was identified upon bacterial genome annotation.

Matched MeSH terms: Bacillus
Selection and evaluation of Malaysian Bacillus spp. strains as potential probiotics in cultured tiger grouper (Epinephelus fuscoguttatus)

Yasin IM, Razak NF, Natrah FMI, Harmin SA

J Environ Biol, 2016 07;37(4 Spec No):791-800.
PMID: 28779739

A total of 58 Gram-positive bacteria strains were isolated from the marine environment and screened for potential probiotics for disease prevention and improving the productivity of tiger grouper Epinephelus fuscoguttatus larvae and juveniles. The bacteria were identified as Bacillus licheniformis, B. subtilis, B. circulans, B. sphaericus, B. cereus, Brevibacillus brevis, Corynebacterium propinquum, Leifsonia aquatica and Paenibacillus macerans. Only 24 strains showed antagonistic activities against four pathogenic strains; Vibrio alginolyticus, V. harveyi, V. parahaemolyticus and Aeromonas hydrophila, where two of the Bacillus strains, B12 and B45 demonstrated intermediate to highest level of inhibitory activity against these pathogenic strains, respectively. Further assessment by co-culture assay showed that Bacillus strain B12 exhibited a total inhibition of V. alginolyticus, while B45 strain displayed no inhibitory activity. Mixed culture of Bacillus B12 and B45 strains to outcompete V. alginolyticus was observed at a cell density of 10(7) CFU ml(-1). Molecular identification and phylogenetic tree analysis have categorized Bacillus strain B12 to the reference strains GQ340480 and JX290193 of? B. amyloliquafaciens, and Bacillus strain B45 with a reference strain JF496522 of B. subtilis. Safety tests of probionts by intraperitoneal administration of B12 and B45 strains at cell densities of 103, 105 and 10(7) CFU ml(-1) revealed no abnormalities and cent percent survival for healthy Epinephelus fuscoguttatus juveniles within 15 days of experimental period. Overall, the study revealed that Bacillus B12 strain possesses tremendous probiotic potential that could be used as a feed supplement in tiger grouper diets. ?

Matched MeSH terms: Bacillus/classification*; Bacillus/genetics; Bacillus/physiology
Fulltext Kinetics of molybdenum reduction to molybdenum blue by Bacillus sp. strain A.rzi

Othman AR, Bakar NA, Halmi MI, Johari WL, Ahmad SA, Jirangon H, et al.

Biomed Res Int, 2013;2013:371058.
PMID: 24369531 DOI: 10.1155/2013/371058

Molybdenum is very toxic to agricultural animals. Mo-reducing bacterium can be used to immobilize soluble molybdenum to insoluble forms, reducing its toxicity in the process. In this work the isolation of a novel molybdate-reducing Gram positive bacterium tentatively identified as Bacillus sp. strain A.rzi from a metal-contaminated soil is reported. The cellular reduction of molybdate to molybdenum blue occurred optimally at 4 mM phosphate, using 1% (w/v) glucose, 50 mM molybdate, between 28 and 30 °C and at pH 7.3. The spectrum of the Mo-blue product showed a maximum peak at 865 nm and a shoulder at 700 nm. Inhibitors of bacterial electron transport system (ETS) such as rotenone, sodium azide, antimycin A, and potassium cyanide could not inhibit the molybdenum-reducing activity. At 0.1 mM, mercury, copper, cadmium, arsenic, lead, chromium, cobalt, and zinc showed strong inhibition on molybdate reduction by crude enzyme. The best model that fitted the experimental data well was Luong followed by Haldane and Monod. The calculated value for Luong's constants p max, K(s), S(m), and n was 5.88 μmole Mo-blue hr(-1), 70.36 mM, 108.22 mM, and 0.74, respectively. The characteristics of this bacterium make it an ideal tool for bioremediation of molybdenum pollution.

Matched MeSH terms: Bacillus/isolation & purification; Bacillus/metabolism*; Bacillus/chemistry
Fulltext Antibacterial activity of different degree of hydrolysis of palm kernel expeller peptides against spore-forming and non-spore-forming bacteria

Tan YN, Ayob MK, Osman MA, Matthews KR

Lett Appl Microbiol, 2011 Nov;53(5):509-17.
PMID: 21848644 DOI: 10.1111/j.1472-765X.2011.03137.x

The goal of this study was to determine inhibitory effect of palm kernel expeller (PKE) peptides of different degree of hydrolysis (DH %) against spore-forming bacteria Bacillus cereus, Bacillus circulans, Bacillus coagulans, Bacillus licheniformis, Bacillus megaterium, Bacillus pumilus, Bacillus stearothermophillus, Bacillus subtilis, Bacillus thuringiensis, Clostridium perfringens; and non-spore-forming bacteria Escherichia coli, Lisinibacillus sphaericus, Listeria monocytogenes, Pseudomonas aeruginosa, Salmonella Typhimurium and Staphylococcus aureus.

Matched MeSH terms: Bacillus/drug effects; Bacillus/physiology; Bacillus megaterium/drug effects; Bacillus subtilis/drug effects
Isolation and characterization of an acrylamide-degrading Bacillus cereus

Shukor MY, Gusmanizar N, Azmi NA, Hamid M, Ramli J, Shamaan NA, et al.

J Environ Biol, 2009 Jan;30(1):57-64.
PMID: 20112864

Several local acrylamide-degrading bacteria have been isolated. One of the isolate that exhibited the highest growth on acrylamide as a nitrogen source was then further characterized. The isolate was tentatively identified as Bacillus cereus strain DRY135 based on carbon utilization profiles using Biolog GP plates and partial 16S rDNA molecular phylogeny. The isolate grew optimally in between the temperatures of 25 and 30 degrees C and within the pH range of 6.8 to 7.0. Glucose, fructose, lactose, maltose, mannitol, citric acid and sucrose supported growth with glucose being the best carbon source. Different concentrations of acrylamide ranging from 100 to 4000 mg l(-1) incorporated into the growth media shows that the highest growth was obtained at acrylamide concentrations of between 500 to 1500 mg l(-1). At 1000 mg l(-1) of acrylamide, degradation was 90% completed after ten days of incubation with concomitant cell growth. The metabolite acrylic acid was detected in the media during degradation. Other amides such as methacrylamide, nicotinamide, acetamide, propionamide and urea supported growth with the highest growth supported by acetamide, propionamide and urea. Strain DRY135, however was not able to assimilate 2-chloroacetamide. The characteristics of this isolate suggest that it would be useful in the bioremediation of acrylamide.

Matched MeSH terms: Bacillus cereus/genetics; Bacillus cereus/growth & development; Bacillus cereus/isolation & purification; Bacillus cereus/metabolism*
Prevalence of Bacillus cereus in selected foods and detection of enterotoxin using TECRA-VIA and BCET-RPLA

Rusul G, Yaacob NH

Int J Food Microbiol, 1995 Apr;25(2):131-9.
PMID: 7547144

Enterotoxigenic Bacillus cereus was detected in cooked foods (17), rice noodles (3), wet wheat noodles (2), dry wheat noodles (10), spices (8), grains (4), legumes (11) and legume products (3). One hundred ninety-four (42.3%), 70 (15.3%) and 23 (5.2%) of the 459 presumptive B. cereus colonies isolated from PEMBA agar were identified as B. cereus, Bacillus thuringiensis and B. mycoides, respectively. B. cereus isolates were examined for growth temperature, pH profile and enterotoxin production using both TECRA-VIA and BCET-RPLA kits. One hundred seventy-eight (91.8%) and 164 (84%) of the strains were enterotoxigenic as determined using TECRA-VIA and BCET-RPLA, respectively. Eighty-two (50%) of the enterotoxigenic strains were capable of growing at 5 degrees C, and 142 (86.6%) grew at 7 degrees C within 7 days of incubation. The enterotoxigenic strains did not grow at pH 4.0 but 69 (42.0%) of the strains were able to grow at pH 4.5 within 7 days at 37 degrees C. The isolates were resistant to ampicillin (98.8%), cloxallin (100%) and tetracycline (61.0%), and susceptible to chloroamphenicol (87%), erythromycin (77.4%), gentamycin (100%) and streptomycin (98.7%).

Matched MeSH terms: Bacillus cereus/drug effects; Bacillus cereus/growth & development; Bacillus cereus/isolation & purification*; Bacillus cereus/metabolism
Danger lurking in the "unknowns": structure-to-function studies of hypothetical protein Bleg1_2437 from Bacillus lehensis G1 alkaliphile revealed an evolutionary divergent B3 metallo-beta-lactamase

Tan SH, Normi YM, Leow AT, Salleh AB, Murad AM, Mahadi NM, et al.

J. Biochem., 2017 02 01;161(2):167-186.
PMID: 28175318 DOI: 10.1093/jb/mvw058

The effectiveness of β-lactam antibiotics as chemotherapeutic agents to treat bacterial infections is gradually threatened with the emergence of antibiotic resistance mechanism among pathogenic bacteria through the production metallo-β-lactamase (MBL). In this study, we discovered a novel hypothetical protein (HP) termed Bleg1_2437 from the genome of alkaliphilic Bacillus lehensis G1 which exhibited MBL-like properties of B3 subclass; but evolutionary divergent from other circulating B3 MBLs. Domain and sequence analysis of HP Bleg1_2437 revealed that it contains highly conserved Zn2+-binding residues such as H54, H56, D58, H59, H131 and H191, important for catalysis, similar with the subclass B3 of MBL. Built 3-D Bleg1_2437 structure exhibited an αββα sandwich layer similar to the well-conserved global topology of MBL superfamily. Other features include a ceiling and floor in the model which are important for accommodation and orientation of β-lactam antibiotics docked to the protein model showed interactions at varying degrees with residues in the binding pocket of Bleg1_2437. Hydrolysis activity towards several β-lactam antibiotics was proven through an in vitro assay using purified recombinant Bleg1_2437 protein. These findings highlight the presence of a clinically important and evolutionary divergent antibiotics-degrading enzyme within the pools of uncharacterized HPs.

Matched MeSH terms: Bacillus/drug effects; Bacillus/enzymology*; Bacillus/genetics; Bacillus/metabolism
Fulltext Binary Toxin Subunits of Lysinibacillus sphaericus Are Monomeric and Form Heterodimers after In Vitro Activation

Surya W, Chooduang S, Choong YK, Torres J, Boonserm P

PLoS One, 2016;11(6):e0158356.
PMID: 27341696 DOI: 10.1371/journal.pone.0158356

The binary toxin from Lysinibacillus sphaericus has been successfully used for controlling mosquito-transmitted diseases. An activation step shortens both subunits BinA and BinB before their interaction with membranes and internalization in midgut cells, but the precise role of this activation step is unknown. Herein, we show conclusively using three orthogonal biophysical techniques that protoxin subunits form only monomers in aqueous solution. However, in vitro activated toxins readily form heterodimers. This oligomeric state did not change after incubation of these heterodimers with detergent. These results are consistent with the evidence that maximal toxicity in mosquito larvae is achieved when the two subunits, BinA and BinB, are in a 1:1 molar ratio, and directly link proteolytic activation to heterodimerization. Formation of a heterodimer must thus be necessary for subsequent steps, e.g., interaction with membranes, or with a suitable receptor in susceptible mosquito species. Lastly, despite existing similarities between BinB C-terminal domain with domains 3 and 4 of pore-forming aerolysin, no aerolysin-like SDS-resistant heptameric oligomers were observed when the activated Bin subunits were incubated in the presence of detergents or lipidic membranes.

Matched MeSH terms: Bacillus/metabolism*
Fulltext Biodegradation of palm kernel cake by cellulolytic and hemicellulolytic bacterial cultures through solid state fermentation

Alshelmani MI, Loh TC, Foo HL, Lau WH, Sazili AQ

ScientificWorldJournal, 2014;2014:729852.
PMID: 25019097 DOI: 10.1155/2014/729852

Four cellulolytic and hemicellulolytic bacterial cultures were purchased from the Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Culture (DSMZ) and the American Type Culture Collection (ATCC). Two experiments were conducted; the objective of the first experiment was to determine the optimum time period required for solid state fermentation (SSF) of palm kernel cake (PKC), whereas the objective of the second experiment was to investigate the effect of combinations of these cellulolytic and hemicellulolytic bacteria on the nutritive quality of the PKC. In the first experiment, the SSF was lasted for 12 days with inoculum size of 10% (v/w) on different PKC to moisture ratios. In the second experiment, fifteen combinations were created among the four microbes with one untreated PKC as a control. The SSF lasted for 9 days, and the samples were autoclaved, dried, and analyzed for proximate analysis. Results showed that bacterial cultures produced high enzymes activities at the 4th day of SSF, whereas their abilities to produce enzymes tended to be decreased to reach zero at the 8th day of SSF. Findings in the second experiment showed that hemicellulose and cellulose was significantly (P < 0.05) decreased, whereas the amount of reducing sugars were significantly (P < 0.05) increased in the fermented PKC (FPKC) compared with untreated PKC.

Matched MeSH terms: Bacillus/metabolism*; Paenibacillus/metabolism*
Fulltext Residual effects of TMOF-Bti formulations against 1(st) instar Aedes aegypti Linnaeus larvae outside laboratory

Saiful AN, Lau MS, Sulaiman S, Hidayatulfathi O

Asian Pac J Trop Biomed, 2012 Apr;2(4):315-9.
PMID: 23569922 DOI: 10.1016/S2221-1691(12)60031-8

To evaluate the effectiveness and residual effects of trypsin modulating oostatic factor-Bacillus thuringiensis israeliensis (TMOF-Bti) formulations against Aedes aegypti (Ae. aegypti) (L.) larvae at UKM Campus Kuala Lumpur.

Matched MeSH terms: Bacillus thuringiensis/chemistry*
Fulltext 3D structure elucidation of thermostable L2 lipase from Thermophilic Bacillus sp. L2

Abd Rahman RN, Shariff FM, Basri M, Salleh AB

Int J Mol Sci, 2012;13(7):9207-17.
PMID: 22942761 DOI: 10.3390/ijms13079207

The crystallization of proteins makes it possible to determine their structure by X-ray crystallography, and is therefore important for the analysis of protein structure-function relationships. L2 lipase was crystallized by using the J-tube counter diffusion method. A crystallization consisting of 20% PEG 6000, 50 mM MES pH 6.5 and 50 mM NaCl was found to be the best condition to produce crystals with good shape and size (0.5 × 0.1 × 0.2 mm). The protein concentration used for the crystallization was 3 mg/mL. L2 lipase crystal has two crystal forms, Shape 1 and Shape 2. Shape 2 L2 lipase crystal was diffracted at 1.5 Å and the crystal belongs to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 72.0, b = 81.8, c = 83.4 Å, α = β = γ = 90°. There is one molecule per asymmetric unit and the solvent content of the crystals is 56.9%, with a Matthew's coefficient of 2.85 Å Da(-1). The 3D structure of L2 lipase revealed topological organization of α/β-hydrolase fold consisting of 11 β-strands and 13 α-helices. Ser-113, His-358 and Asp-317 were assigned as catalytic triad residues. One Ca(2+) and one Zn(2+) were found in the L2 lipase molecule.

Matched MeSH terms: Bacillus/enzymology*
Isotherm equilibria of Mn²⁺ biosorption in drinking water treatment by locally isolated Bacillus species and sewage activated sludge

Hasan HA, Abdullah SR, Kofli NT, Kamarudin SK

J Environ Manage, 2012 Nov 30;111:34-43.
PMID: 22813857 DOI: 10.1016/j.jenvman.2012.06.027

Manganese (Mn(2+)) is one of the inorganic contaminant that causes problem to water treatment and water distribution due to the accumulation on water piping systems. In this study, Bacillus sp. and sewage activated sludge (SAS) were investigated as biosorbents in laboratory-scale experiments. The study showed that Bacillus sp. was a more effective biosorbent than SAS. The experimental data were fitted to the Langmuir (Langmuir-1 & Langmuir-2), Freundlich, Temkin, Dubinin-Radushkevich (D-R) and Redlich-Peterson (R-P) isotherms to obtain the characteristic parameters of each model. Mn(2+) biosorption by Bacillus sp. was found to be significantly better fitted to the Langmuir-1 isotherm than the other isotherms, while the D-R isotherm was the best fit for SAS; i.e., the χ(2) value was smaller than that for the Freundlich, Temkin, and R-P isotherms. According to the evaluation using the Langmuir-1 isotherm, the maximum biosorption capacities of Mn(2+) onto Bacillus sp. and SAS were 43.5 mg Mn(2+)/g biomass and 12.7 mg Mn(2+)/g biomass, respectively. The data fitted using the D-R isotherm showed that the Mn(2+) biosorption processes by both Bacillus sp. and SAS occurred via the chemical ion-exchange mechanism between the functional groups and Mn(2+) ion.

Matched MeSH terms: Bacillus/metabolism*
Dietary administration of Bacillus thuringiensis on the cellular innate immune response of African catfish (Clarias gariepinus) against Aeromonas hydrophila

Reneshwary C, Rajalakshmi M, Marimuthu K, Xavier R

Eur Rev Med Pharmacol Sci, 2011 Jan;15(1):53-60.
PMID: 21381499

An experiment was conducted to evaluate the use of Bacillus thuringiensis (Bt) as a probiotic to enhance the cellular innate immune response of the African catfish (Clarias gariepinus) challenged with a bacterial fish pathogen, Aeromonas hydrophila.

Matched MeSH terms: Bacillus thuringiensis/immunology*

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