AMB Express

http://link.springer.com/journal/13568

List of Papers (Total 646)

Antimicrobial activity of puffball(Bovistella radicata) and separation of bioactive compounds

Background To test the antimicrobial activity of different extracts and fermentation broth from puffball(Bovistella radicata), the different extracts and fermentation broth of puffball were prepared, the active fraction was investigated by UPLC–UV–MS and semi-preparative chromatograph. Results Through zones of inhibition (ZOI) and minimum inhibitory concentrations (MIC) tests, the ...

Development of a dual-expression vector facilitated with selection-free PCR recombination cloning strategy

The conventional procedure for the construction of recombinant expression vector of a target gene includes PCR cloning and restriction enzyme mediated subcloning, which is time-consuming and sometimes troublesome because of the inefficiency of ligation. A variety of ligase-independent PCR cloning strategies have been developed, but they either involve complicated PCR procedures or ...

Improving the temperature characteristics and catalytic efficiency of a mesophilic xylanase from Aspergillus oryzae, AoXyn11A, by iterative mutagenesis based on in silico design

To improve the temperature characteristics and catalytic efficiency of a glycoside hydrolase family (GHF) 11 xylanase from Aspergillus oryzae (AoXyn11A), its variants were predicted based on in silico design. Firstly, Gly21 with the maximum B-factor value, which was confirmed by molecular dynamics (MD) simulation on the three-dimensional structure of AoXyn11A, was subjected to ...

Application of response surface methodology for optimization of medium components for the production of secondary metabolites by Streptomyces diastatochromogenes KX852460

A bioactive strain Streptomyces diastatochromogenes KX852460 was selected for the production of secondary metabolites to control the target spot disease on tobacco leaves, caused by the Rhizoctonia solani AG-3. Peanut meal, soluble starch, NaCl, yeast extract, and ammonium sulphate were identified the best ingredient for high antifungal activity of S. diastatochromogenes KX852460 ...

Novel signal peptides improve the secretion of recombinant Staphylococcus aureus Alpha toxinH35L in Escherichia coli

Secretion of heterologous proteins into Escherichia coli cell culture medium offers significant advantages for downstream processing over production as inclusion bodies; including cost and time savings, and reduction of endotoxin. Signal peptides play an important role in targeting proteins for translocation across the cytoplasmic membrane to the periplasmic space and release into ...

Medium-chain-length polyhydroxyalkanoates synthesis by Pseudomonas putida KT2440 relA/spoT mutant: bioprocess characterization and transcriptome analysis

Pseudomonas putida KT2440 is a model bacteria used commonly for medium-chain-length polyhydroxyalkanoates (mcl-PHAs) production using various substrates. However, despite many studies conducted on P. putida KT2440 strain, the molecular mechanisms of leading to mcl-PHAs synthesis in reaction to environmental stimuli are still not clear. The rearrangement of the metabolism in ...

Systematic analysis of the lysine acetylome reveals diverse functions of lysine acetylation in the oleaginous yeast Yarrowia lipolytica

Lysine acetylation of proteins, a major post-translational modification, plays a critical regulatory role in almost every aspects in both eukaryotes and prokaryotes. Yarrowia lipolytica, an oleaginous yeast, is considered as a model for bio-oil production due to its ability to accumulate a large amount of lipids. However, the function of lysine acetylation in this organism is ...

Autolysis of Pichia pastoris induced by cold

The production of recombinant biopharmaceutical proteins is a multi-billion dollar market. Protein recovery represents a major part of the production costs. Pichia pastoris is one of the microbial systems most used for the production of heterologous proteins. The use of a cold-induced promoter to express lytic enzymes in the yeast after the growth stage could reduce protein ...

Cysteine degradation gene yhaM, encoding cysteine desulfidase, serves as a genetic engineering target to improve cysteine production in Escherichia coli

Cysteine is an important amino acid for various industries; however, there is no efficient microbial fermentation-based production method available. Owing to its cytotoxicity, bacterial intracellular levels of cysteine are stringently controlled via several modes of regulation, including cysteine degradation by cysteine desulfhydrases and cysteine desulfidases. In Escherichia coli, ...

Role of nitrite in the competition between denitrification and DNRA in a chemostat enrichment culture

Denitrification and dissimilatory nitrate reduction to ammonium (DNRA) are two microbial processes that compete for oxidized nitrogen compounds in the environment. The objective of this work was to determine the role of nitrite versus nitrate as terminal electron acceptor on the competition between DNRA and denitrification. Initially, a mixed culture chemostat was operated under ...

Enhanced methane production of vinegar residue by response surface methodology (RSM)

As the by-product of the vinegar production process, a large number of vinegar residue has been abandoned and caused a serious environmental pollution. Anaerobic digestion has been proved to be able to dispose and convert vinegar residue into bioenergy but still need to improve the efficiency. This study applied central composite design of response surface methodology to ...

Cloning and characterization of the Type I Baeyer–Villiger monooxygenase from Leptospira biflexa

Baeyer–Villiger monooxygenases are recognized by their ability and high selectivity as oxidative biocatalysts for the generation of esters or lactones using ketones as starting materials. These enzymes represent valuable tools for biooxidative syntheses since they can catalyze reactions that otherwise involve strong oxidative reagents. In this work, we present a novel enzyme, the ...

Biocatalytic activity of Monascus mycelia depending on physiology and high sensitivity to product concentration

Cell suspension culture using mycelia as whole cell biocatalyst for production of orange Monascus pigments has been carried out successfully in a nonionic surfactant micelle aqueous solution. Thus, selection of mycelia as whole cell biocatalyst and the corresponding enzymatic kinetics for production of orange Monascus pigments can be optimized independently. Mycelia selected from ...

Heterologous expression of a Streptomyces cyaneus laccase for biomass modification applications

Laccases are used for the conversion of biomass into fermentable sugars but it is difficult to produce high yields of active laccases in heterologous expression systems. We overcame this challenge by expressing Streptomyces cyaneus CECT 3335 laccase in Escherichia coli (ScLac) and we achieved a yield of up to 104 mg L−1 following purification by one-step affinity chromatography. ...

Growth kinetics, fatty acid composition and metabolic activity changes of Crypthecodinium cohnii under different nitrogen source and concentration

The effect of varying concentrations of the nitrogen source on the growth kinetics, lipid accumulation, lipid and DHA productivity, and fatty acid composition of C. cohnii was elucidated. Growth of C. cohnii was in three distinct growth stages: cell growth, lipid accumulation and a final lipid turnover stage. Most of lipids were accumulated in lipid accumulation stage (48–120 h) ...

Hydrogen production and microbial kinetics of Clostridium termitidis in mono-culture and co-culture with Clostridium beijerinckii on cellulose

Cellulose utilization by hydrogen producers remains an issue due to the low hydrogen yields reported and the pretreatment of cellulose prior to fermentation requires complex and expensive steps. Clostridium termitidis is able to breakdown cellulose into glucose and produce hydrogen. On the other hand, Clostridium beijerinckii is not able to degrade cellulose but is adept at ...

Ammonia production from amino acid-based biomass-like sources by engineered Escherichia coli

The demand for ammonia is expected to increase in the future because of its importance in agriculture, industry, and hydrogen transportation. Although the Haber–Bosch process is known as an effective way to produce ammonia, the process is energy-intensive. Thus, an environmentally friendly ammonia production process is desired. In this study, we aimed to produce ammonia from amino ...

Characterization of the gut microbiota in the golden takin (Budorcas taxicolor bedfordi)

The gut microbiota of mammals is a complex ecosystem, which is essential for maintaining gut homeostasis and the host’s health. The high throughput sequencing allowed us to gain a deeper insight into the bacterial structure and diversity. In order to improve the health status of the endangered golden takins, we first characterized the fecal microbiota of healthy golden takins using ...

Lachnospiraceae shift in the microbial community of mice faecal sample effects on water immersion restraint stress

Stress, including both psychological and physical stimulation, can cause changes in the microbiota and mucosal function of the gastrointestinal system. There are few research studies available about the faecal microbiota changes after stress, such as water immersion restraint stress (WIRS). Therefore, in this study, we focused on analysing the composition changes of faecal ...

Quantitative detection of fecal contamination with domestic poultry feces in environments in China

Poultry are an important source of fecal contamination in environments. However, tools for detecting and tracking this fecal contamination are in the early stages of development. In practice, we have found that source tracking methods targeting the 16S rRNA genes of poultry-specific microbiota are not sufficiently sensitive. We therefore developed two quantitative PCR assays for ...

Metabolism and secretion of yellow pigment under high glucose stress with Monascus ruber

The biosynthesis of microbial secondary metabolites is induced by a wide range of environmental stresses. In this study, submerged fermentation of Monascus yellow pigments by Monascus ruber CGMCC 10910 under high glucose stress was investigated. The increase of lipid content was the major contributor to the increase of dry cell weight (DCW), and the lipid-free DCW was only slightly ...

Degradation and inactivation of Shiga toxins by nitrogen gas plasma

Shiga toxin (Stx)-producing Escherichia coli (STEC) leads to food poisoning by causing hemorrhagic colitis and hemolytic uremic syndrome. Some STEC produce Shiga toxin 1 (Stx1) and/or Shiga toxin 2 (Stx2), a relatively stable protein toxin, necessitating the development of an efficient inactivation method. Here we applied a nitrogen gas plasma apparatus to the inactivation of Stx. ...

Genomic and molecular characterization of a novel quorum sensing molecule in Bacillus licheniformis

Quorum sensing molecules (QSMs) are involved in the regulation of complicated processes helping bacterial populations respond to changes in their cell-density. Although the QS gene cluster (comQXPA) has been identified in the genome sequence of some bacilli, the QS system B. licheniformis has not been investigated in detail, and its QSM (ComX pheromone) has not been identified. ...

Microbial community compositions in the gastrointestinal tract of Chinese Mongolian sheep using Illumina MiSeq sequencing revealed high microbial diversity

Chinese Mongolian sheep are an important ruminant raised for wool and meat production. However, little is known about the microbiota of the gastrointestinal tract (GIT) of Chinese Mongolian sheep. To increase our understanding of the microbial community composition in the GIT of Chinese Mongolian sheep, microbiota of five sheep is investigate for the first time using the Illumina ...

Nitrate decreases methane production also by increasing methane oxidation through stimulating NC10 population in ruminal culture

Studies proved that addition of nitrate in rumen could lead to reduction of methane emission. The mechanism of this function was involved in the competition effect of nitrate on hydrogen consumption and the inhibitory effect of generated nitrite on methanogen proliferation. The present study investigated an alternative mechanism that denitrifying anaerobic methane oxidizing (DAMO) ...