Bacterial and archaeal diversity in two hot spring microbial mats from the geothermal region of Tengchong, China.

We investigated the bacterial and archaeal diversity in two hot spring microbial mats from the geothermal region of Tengchong in the Yunnan Province, China, using direct molecular analyses. The Langpu (LP) laminated mat was found by the side of a boiling pool with temperature of 60-65 °C and a pH of 8.5, while the Tengchong (TC) streamer mat consisted of white streamers in a slightly acidic (pH 6.

Ectopic expression of a bacterium NhaD-type Na+/H+ antiporter leads to increased tolerance to combined salt/alkali stresses.

AaNhaD, a gene isolated from the soda lake alkaliphile Alkalimonas amylolytica, encodes a Na(+) /H(+) antiporter crucial for the bacterium's resistance to salt/alkali stresses. However, it remains unknown whether this type of bacterial gene may be able to increase the tolerance of flowering plants to salt/alkali stresses. To investigate the use of extremophile genetic resources in higher plants, transgenic tobacco BY-2 cells and plants harboring AaNhaD were generated and their stress tolerance was evaluated.

Efficient production of L-lactic acid with high optical purity by alkaliphilic Bacillus sp. WL-S20.

Highly efficient polymer-grade L-lactic acid production was achieved by an alkaliphilic strain Bacillus sp. WL-S20 using inexpensive peanut meal as nitrogen source and sodium hydroxide as neutralizing agent. In multi-pulse fed-batch fermentation of Bacillus sp.

Designing and creating a modularized synthetic pathway in cyanobacterium Synechocystis enables production of acetone from carbon dioxide.

Ketones are a class of important organic compounds. As the simplest ketone, acetone is widely used as solvents or precursors for industrial chemicals. Presently, million tonnes of acetone is produced worldwide annually, from petrochemical processes.

Crystal structures of D-psicose 3-epimerase from Clostridium cellulolyticum H10 and its complex with ketohexose sugars.

D-psicose 3-epimerase (DPEase) is demonstrated to be useful in the bioproduction of D-psicose, a rare hexose sugar, from D-fructose, found plenty in nature. Clostridium cellulolyticum H10 has recently been identified as a DPEase that can epimerize D-fructose to yield D-psicose with a much higher conversion rate when compared with the conventionally used DTEase. In this study, the crystal structure of the C.

Crystal structure and substrate-binding mode of a novel pectate lyase from alkaliphilic Bacillus sp. N16-5.

The pectate lyase (Bsp165PelA) from Bacillus sp. N16-5 has great potential in industrial applications because it shows high specific activity under extremely alkaline conditions. Besides, activity measurement of Bsp165PelA does not require addition of calcium, in a way different from the other pectate lyases.

[Purification and characterization of mannanase from an alkaliphilic mannanase producing bacterium HMTS15].

Objective: To isolate and identify an alkaliphilic mannanase producing bacterium, purify and characterize mannanase thereof.

Methods: Mannanase-producing alkaliphilic bacterium HMTS15 was isolated by alkaline agar with konjak from water sample of Hamatai Lake in Inner Mongolia, China. The morphological, biochemical and physiological characteristics and 16S rRNA gene were analyzed to identify the taxonomic position of strain HMTS15.

Efficient production of polymer-grade L-lactic acid from corn stover hydrolyzate by thermophilic Bacillus sp. strain XZL4.

Lactic acid has been identified as one of the top 30 potential building-block chemicals from biomass. Therefore, the search for cheap raw materials is an objective to reduce the production costs. Efficient polymer-grade L-lactic acid production was achieved in this report by a thermophilic strain Bacillus sp.

Enhanced activity of Thermotoga maritima cellulase 12A by mutating a unique surface loop.

Cellulase 12A from Thermotoga maritima (TmCel12A) is a hyperthermostable β-1,4-endoglucanase. We recently determined the crystal structures of TmCel12A and its complexes with oligosaccharides. Here, by using site-directed mutagenesis, the role played by Arg60 and Tyr61 in a unique surface loop of TmCel12A was investigated.

Protoplast transformation of recalcitrant alkaliphilic Bacillus sp. with methylated plasmid DNA and a developed hard agar regeneration medium.

Among the diverse alkaliphilic Bacillus strains, only a little have been reported to be genetically transformed. In this study, an efficient protoplast transformation procedure was developed for recalcitrant alkaliphilic Bacillus sp. N16-5.

Genome sequence of Lactobacillus rhamnosus strain CASL, an efficient L-lactic acid producer from cheap substrate cassava.

Lactobacillus rhamnosus is a type of probiotic bacteria with industrial potential for L-lactic acid production. We announce the draft genome sequence of L. rhamnosus CASL (2,855,156 bp with a G+C content of 46.

Combinatorial strategy of sorbitol feeding and low-temperature induction leads to high-level production of alkaline β-mannanase in Pichia pastoris.

A process for efficient production of an alkaline β-mannanases from Bacillus sp. N16-5 was established by heterologous expression using Pichia pastoris. A high producing strain was generated by removing the native β-mannanases signal peptide and increasing the copy number of the mature β-mannanases gene.

Effects of salts on activity of halophilic cellulase with glucomannanase activity isolated from alkaliphilic and halophilic Bacillus sp. BG-CS10.

Alkaliphilic and halophilic Bacillus sp. BG-CS10 was isolated from Zabuye Salt Lake, Tibet. The gene celB, encoding a halophilic cellulase was identified from the genomic library of BG-CS10.

Rational design to improve thermostability and specific activity of the truncated Fibrobacter succinogenes 1,3-1,4-β-D-glucanase.

1,3-1,4-β-D-Glucanase has been widely used as a feed additive to help non-ruminant animals digest plant fibers, with potential in increasing nutrition turnover rate and reducing sanitary problems. Engineering of enzymes for better thermostability is of great importance because it not only can broaden their industrial applications, but also facilitate exploring the mechanism of enzyme stability from structural point of view. To obtain enzyme with higher thermostability and specific activity, structure-based rational design was carried out in this study.

Genome of alkaliphilic Bacillus pseudofirmus OF4 reveals adaptations that support the ability to grow in an external pH range from 7.5 to 11.4.

Bacillus pseudofirmus OF4 is an extreme but facultative alkaliphile that grows non-fermentatively in a pH range from 7.5 to above 11.4 and can withstand large sudden increases in external pH.

A thermostable esterase from Thermoanaerobacter tengcongensis opening up a new family of bacterial lipolytic enzymes.

An unidentified α/β hydrolase gene lipA3 from thermostable eubacterium species Thermoanaerobacter tengcongensis MB4 was cloned and heterologously expressed by Escherichia coli BL21(DE3)pLysS. The purified recombinant enzyme EstA3 turned out to be a monomeric thermostable esterase with optimal activity at 70°C and pH 9.5.

Diverse substrate recognition mechanism revealed by Thermotoga maritima Cel5A structures in complex with cellotetraose, cellobiose and mannotriose.

The hyperthermophilic endoglucanase Cel5A from Thermotoga maritima can find applications in lignocellulosic biofuel production, because it catalyzes the hydrolysis of glucan- and mannan-based polysaccharides. Here, we report the crystal structures in apo-form and in complex with three ligands, cellotetraose, cellobiose and mannotriose, at 1.29Å to 2.

Complete genome sequence of Clostridium acetobutylicum DSM 1731, a solvent-producing strain with multireplicon genome architecture.

Clostridium acetobutylicum is an important microorganism for solvent production. We report the complete genome sequence of C. acetobutylicum DSM 1731, a genome with multireplicon architecture.

Crystal structure of histidine-containing phosphocarrier protein from Thermoanaerobacter tengcongensis MB4 and the implications for thermostability.

Protein thermostability is an inherent characteristic of proteins from thermophilic microorganisms, and therefore enables these organisms to survive at extreme temperatures. Although it is well-known that thermostable proteins are critical for the growth of thermophilic organisms, the structural basis of protein thermostability is not yet fully understood. The histidine-containing phosphocarrier (HPr) protein, a phosphate shuttle protein in the phosphoenolpyruvate-dependent sugar transport system (PTS) of bacterial species, is an ideal model for investigating protein thermostability with respect to its small size and deficiency in disulphide bonds or cofactors.

Genome sequence of the thermophilic strain Bacillus coagulans 2-6, an efficient producer of high-optical-purity L-lactic acid.

Bacillus coagulans 2-6 is an efficient producer of lactic acid. The genome of B. coagulans 2-6 has the smallest genome among the members of the genus Bacillus known to date.

Bacillus daliensis sp. nov., an alkaliphilic, Gram-positive bacterium isolated from a soda lake.

A Gram-positive, alkaliphilic bacterium, designated strain DLS13T, was isolated from Dali Lake in Inner Mongolia Autonomous Region, China. The isolate was able to grow at pH 7.5-11.

Monitoring the microbial community during solid-state acetic acid fermentation of Zhenjiang aromatic vinegar.

Zhenjiang aromatic vinegar is one of the most famous Chinese traditional vinegars. In this study, change of the microbial community during its fermentation process was investigated. DGGE results showed that microbial community was comparatively stable, and the diversity has a disciplinary series of changes during the fermentation process.

Effects of continuous thermophilic composting (CTC) on bacterial community in the active composting process.

The method of continuous thermophilic composting (CTC) remarkably shortened the active composting cycle and enhanced the compost stability. Effects of CTC on the quantities of bacteria, with a comparison to the traditional composting (TC) method, were explored by plate count with incubation at 30, 40 and 50°C, respectively, and by quantitative PCR targeting the universal bacterial 16S rRNA genes and the Bacillus 16S rRNA genes. The comparison of cultivatable or uncultivatable bacterial numbers indicated that CTC might have increased the biomass of bacteria, especially Bacillus spp.

Directed evolution of a thermophilic endoglucanase (Cel5A) into highly active Cel5A variants with an expanded temperature profile.

Cel5A is a highly active endoglucanase from Thermoanaerobacter tengcongensis MB4, displaying an optimal temperature range between 75 and 80°C. After three rounds of error-prone PCR and screening of 4700 mutants, five variants of Cel5A with improved activities were identified by Congo Red based screening method. Compared with the wild type, the best variants 3F6 and C3-13 display 135±6% and 193±8% of the wild type specific activity for the substrate carboxymethyl cellulose (CMC), besides improvements in the relative expression level in Escherichia coli system.