One Gram-positive bacteria,Bacillus sp.strain BG-CSN,was isolated from the muds with hypersaline and alkaline water at the beach of Banger Soda Lake in Tibet,China.After cultivating in liquid medium for 48 hours,an ex...One Gram-positive bacteria,Bacillus sp.strain BG-CSN,was isolated from the muds with hypersaline and alkaline water at the beach of Banger Soda Lake in Tibet,China.After cultivating in liquid medium for 48 hours,an extracellular α-amylase AmyBGC from the strain BG-CSN was purified 23-fold reaching to electrophoretic homogeneity by sequentially ammonium sulfate precipitation,Octyl-Sepharose CL-4B column chromatography,DEAE-Sepharose Fast Flow chromatography,DEAE-Toyopearl 650M chromatography and Sephadex G-100 chromatography.The enzyme had a molecular mass of 87 kD estimated by SDS-PAGE.The enzyme was optimally active at pH 10.5 and 52.5℃ and showed stability at pH range of 5.0 to 11.5 at the temperature below 35℃. The enzyme activity was inhibited by Hg+ and Fe 3+.The activity was not prevented at all by chelating reagents EDTA and SDS at high concentrations.This enzyme efficiently hydrolyzed starch to yield a series of maltooligosaccharides,including maltose after completion of the reaction.These results indicate that AmyBGC is classified as a liquefying endo-1,4-D-α-amylase(EC-3.2.1.1).展开更多
The novel alkaliphilic strain, designated as Bacillus sp. IB-OR17 and isolated from soda lake sediments, was identified and characterized. Isolated strain demonstrated slight antifungal activity against some plant pat...The novel alkaliphilic strain, designated as Bacillus sp. IB-OR17 and isolated from soda lake sediments, was identified and characterized. Isolated strain demonstrated slight antifungal activity against some plant pathogen fungi that are capable to grow under alkaline conditions. Based on its morphological, physiological and biochemical characteristics as well as on 16S rRNA gene analysis data, Bacillus sp. IB-OR17 were related to alkaliphilic species B. mannanilyticus. Such as type species, Bacillus sp. IB-OR17 produced extracellular β-mannanase but additionally it displayed also chitinolytic activity which is a new property reported for this species. Bacillus sp. IB-OR17 grew in pH range 8.0 - 11.0 with maximal intensity under 9.0 - 10.0 but not showed halophilic properties (growth limit under NaCl concentrations < 5%). Maximal production of chitinase is observed at the same pH interval after 96 h of submerged cultivation of the strain. Bacillus sp. IB-OR17 produced chitinase(s) in presence of colloidal chitin as main carbon source and sodium carbonate (0.25% - 1.0%) demonstrating high enzyme yield under enough low concentrations of the substrate (0.20%). Unlike chitinase, β-mannanase was constitutively produced by Bacillus sp. IB- OR17 in presence of various substrates including crab shell chitin. Probable involvement of the enzymes in antifungal activity of Bacillus sp. IB-OR17 is discussed shortly in terms of further researches and application of this strain.展开更多
The diversity of filamentous fungi that can grow at high ambient pH values(i.e.,8–11)remains largely understudied.Here we study 100 alkalitolerant and alkaliphilic isolates from the soils around the basin of soda lak...The diversity of filamentous fungi that can grow at high ambient pH values(i.e.,8–11)remains largely understudied.Here we study 100 alkalitolerant and alkaliphilic isolates from the soils around the basin of soda lakes in Asia and Africa to assess the major evolutionary lineages and morphologies pertinent to the alkaliphilic trait in filamentous fungi.The Emericellopsis lineage(Hypocreales,Hypocreomycetidae),along with Plectosphaerellaceae(Hypocreomycetidae),Pleosporaceae(Dothideomycetes),Chaetomiaceae(Sordariomycetidae)families appeared to be overrepresented with strong alkalitolerants and effective alkaliphiles.In particular,Sodiomyces species(Plectosphaerellaceae),Acrostalagmus luteoalbus(Plectosphaerellaceae),Emericellopsis alkalina(Hypocreales),Thielavia sp.(Chaetomiaceae),and Alternaria sect.Soda(Pleosporaceae)grew best at high ambient pH.The pH tolerance of Chordomyces antarcticum,Acrostalagmus luteoalbus and some other species was largely affected by the presence of extra Na+in the growth medium.Moderate alkalitolerants included Scopulariopsis members(Microascales),Fusarium,Cladosporium,and many asexual acremonium-like species from Bionectriaceae.Weak alkalitolerants were represented by sporadic isolates of Penicillium,Purpureocillium lilacinum,and Alternaria alternata species,with the growth optimum at neutral or acidic pH.Weak alkalitolerants develop loose dry chains of spores easily dispersed by air.Their presence at low frequency with the growth optimum at neutral or acidic pH leads us to treat them as transient species in the alkaline soils,as those are also ubiquitous saprobes in normal soils.Our phylogenetic analyses show that the alkaliphilic trait in filamentous fungi has evolved several times.Several lineages harboring strong alkalitolerants derived from the known marine-borne fungi(Emericellopsis,Alternaria sect.Phragmosporae),or fall within the fungi associated with halophytic grasses(Pleosporaceae).Soda soils contain a diversity of fungi that range from weak alkalitolerant to alkaliphilic,w展开更多
The use of high alkaline medium is a feasible way to provide carbon source and prevent biological contamination for the outdoor cultivation of alkaliphilic microalgae and cyanobacteria.A novel cyanobacterial strain wa...The use of high alkaline medium is a feasible way to provide carbon source and prevent biological contamination for the outdoor cultivation of alkaliphilic microalgae and cyanobacteria.A novel cyanobacterial strain was isolated from the open pond of a marine green alga(Picochlorum sp.SCSIO-45015,Sanya,Hainan)and identified as Cyanobacterium sp.SCSIO-45682.The effects of initial sodium bicarbonate(NaHCO_(3))concentrations on the growth and biochemical composition of Cyanobacterium sp.SCSIO-45682 were investigated.The results demonstrated that Cyanobacterium sp.SCSIO-45682 had good adaptation to 16.8-g/L NaHCO_(3)(the same concentration of NaHCO_(3) used in Zarrouk medium for Spirulina).Moreover,the yields of biomass,polysaccharide,chlorophyll a(chl a),and phycocyanin increased under high NaHCO_(3) concentrations.The maximum final biomass concentration of 2.5 g/L was observed at 8.4-g/L NaHCO_(3),while the highest intracellular total saccharide content of 49.2%of dry weight(DW)and exopolysaccharide(EPS)concentration of 93 mg/L were achieved at the NaHCO_(3) concentration of 16.8 g/L.The crude protein content declined under high NaHCO_(3) concentrations,which provide a possible explanation for the accumulation of polysaccharide.This study shows a good potential of alkaliphilic Cyanobacterium sp.SCSIO-45682 as a polysaccharide feedstock.展开更多
文摘One Gram-positive bacteria,Bacillus sp.strain BG-CSN,was isolated from the muds with hypersaline and alkaline water at the beach of Banger Soda Lake in Tibet,China.After cultivating in liquid medium for 48 hours,an extracellular α-amylase AmyBGC from the strain BG-CSN was purified 23-fold reaching to electrophoretic homogeneity by sequentially ammonium sulfate precipitation,Octyl-Sepharose CL-4B column chromatography,DEAE-Sepharose Fast Flow chromatography,DEAE-Toyopearl 650M chromatography and Sephadex G-100 chromatography.The enzyme had a molecular mass of 87 kD estimated by SDS-PAGE.The enzyme was optimally active at pH 10.5 and 52.5℃ and showed stability at pH range of 5.0 to 11.5 at the temperature below 35℃. The enzyme activity was inhibited by Hg+ and Fe 3+.The activity was not prevented at all by chelating reagents EDTA and SDS at high concentrations.This enzyme efficiently hydrolyzed starch to yield a series of maltooligosaccharides,including maltose after completion of the reaction.These results indicate that AmyBGC is classified as a liquefying endo-1,4-D-α-amylase(EC-3.2.1.1).
文摘The novel alkaliphilic strain, designated as Bacillus sp. IB-OR17 and isolated from soda lake sediments, was identified and characterized. Isolated strain demonstrated slight antifungal activity against some plant pathogen fungi that are capable to grow under alkaline conditions. Based on its morphological, physiological and biochemical characteristics as well as on 16S rRNA gene analysis data, Bacillus sp. IB-OR17 were related to alkaliphilic species B. mannanilyticus. Such as type species, Bacillus sp. IB-OR17 produced extracellular β-mannanase but additionally it displayed also chitinolytic activity which is a new property reported for this species. Bacillus sp. IB-OR17 grew in pH range 8.0 - 11.0 with maximal intensity under 9.0 - 10.0 but not showed halophilic properties (growth limit under NaCl concentrations < 5%). Maximal production of chitinase is observed at the same pH interval after 96 h of submerged cultivation of the strain. Bacillus sp. IB-OR17 produced chitinase(s) in presence of colloidal chitin as main carbon source and sodium carbonate (0.25% - 1.0%) demonstrating high enzyme yield under enough low concentrations of the substrate (0.20%). Unlike chitinase, β-mannanase was constitutively produced by Bacillus sp. IB- OR17 in presence of various substrates including crab shell chitin. Probable involvement of the enzymes in antifungal activity of Bacillus sp. IB-OR17 is discussed shortly in terms of further researches and application of this strain.
基金supported by the Laboratory of Genetics at Wageningen University(The Netherlands),RSCF grant №14-50-00029,RFBR grants №15-04-06975,№15-04-06260(Russia).
文摘The diversity of filamentous fungi that can grow at high ambient pH values(i.e.,8–11)remains largely understudied.Here we study 100 alkalitolerant and alkaliphilic isolates from the soils around the basin of soda lakes in Asia and Africa to assess the major evolutionary lineages and morphologies pertinent to the alkaliphilic trait in filamentous fungi.The Emericellopsis lineage(Hypocreales,Hypocreomycetidae),along with Plectosphaerellaceae(Hypocreomycetidae),Pleosporaceae(Dothideomycetes),Chaetomiaceae(Sordariomycetidae)families appeared to be overrepresented with strong alkalitolerants and effective alkaliphiles.In particular,Sodiomyces species(Plectosphaerellaceae),Acrostalagmus luteoalbus(Plectosphaerellaceae),Emericellopsis alkalina(Hypocreales),Thielavia sp.(Chaetomiaceae),and Alternaria sect.Soda(Pleosporaceae)grew best at high ambient pH.The pH tolerance of Chordomyces antarcticum,Acrostalagmus luteoalbus and some other species was largely affected by the presence of extra Na+in the growth medium.Moderate alkalitolerants included Scopulariopsis members(Microascales),Fusarium,Cladosporium,and many asexual acremonium-like species from Bionectriaceae.Weak alkalitolerants were represented by sporadic isolates of Penicillium,Purpureocillium lilacinum,and Alternaria alternata species,with the growth optimum at neutral or acidic pH.Weak alkalitolerants develop loose dry chains of spores easily dispersed by air.Their presence at low frequency with the growth optimum at neutral or acidic pH leads us to treat them as transient species in the alkaline soils,as those are also ubiquitous saprobes in normal soils.Our phylogenetic analyses show that the alkaliphilic trait in filamentous fungi has evolved several times.Several lineages harboring strong alkalitolerants derived from the known marine-borne fungi(Emericellopsis,Alternaria sect.Phragmosporae),or fall within the fungi associated with halophytic grasses(Pleosporaceae).Soda soils contain a diversity of fungi that range from weak alkalitolerant to alkaliphilic,w
基金Supported by Key-Area Research and Development Program of Guangdong Province(No.2020B1111030004)the Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)(No.GML2019ZD0406)+3 种基金the 13th Five-Year Plan Marine Economy Innovation Development Demonstration Project(No.BHSFS004)the Project of State Key Laboratory of Marine Resource Utilization in South China Sea(No.2018004)the Guizhou Education Department Young scientific talents Promoting Program(No.KY[2016]160)the Project of Danzi(WetCode)Group(No.DZ201501)。
文摘The use of high alkaline medium is a feasible way to provide carbon source and prevent biological contamination for the outdoor cultivation of alkaliphilic microalgae and cyanobacteria.A novel cyanobacterial strain was isolated from the open pond of a marine green alga(Picochlorum sp.SCSIO-45015,Sanya,Hainan)and identified as Cyanobacterium sp.SCSIO-45682.The effects of initial sodium bicarbonate(NaHCO_(3))concentrations on the growth and biochemical composition of Cyanobacterium sp.SCSIO-45682 were investigated.The results demonstrated that Cyanobacterium sp.SCSIO-45682 had good adaptation to 16.8-g/L NaHCO_(3)(the same concentration of NaHCO_(3) used in Zarrouk medium for Spirulina).Moreover,the yields of biomass,polysaccharide,chlorophyll a(chl a),and phycocyanin increased under high NaHCO_(3) concentrations.The maximum final biomass concentration of 2.5 g/L was observed at 8.4-g/L NaHCO_(3),while the highest intracellular total saccharide content of 49.2%of dry weight(DW)and exopolysaccharide(EPS)concentration of 93 mg/L were achieved at the NaHCO_(3) concentration of 16.8 g/L.The crude protein content declined under high NaHCO_(3) concentrations,which provide a possible explanation for the accumulation of polysaccharide.This study shows a good potential of alkaliphilic Cyanobacterium sp.SCSIO-45682 as a polysaccharide feedstock.
