AMB Express

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

List of Papers (Total 646)

An enhanced vector-free allele exchange (VFAE) mutagenesis protocol for genome editing in a wide range of bacterial species

Vector-free allele exchange (VFAE) is a newly developed protocol for genome editing in Pseudomonas species. Although several parameters have been determined to optimize the procedures for obtaining a stable and high-frequency mutation, numerous false-positive clones still appear on the plate, which increases the difficulty of finding the desired mutants. It has also not been ...

Lsp family proteins regulate antibiotic biosynthesis in Lysobacter enzymogenes OH11

Ax21 family proteins have been shown to play regulatory roles in plant- and animal-pathogenic species in the bacterial family Xanthomonadaceae, but the protein have not been investigated previously in the non-pathogenic members of this bacterial family. Lysobacter enzymogenes, is a non-pathogenic species known for its capacity as a biocontrol agent of plant pathogens. It is also ...

Toward a cell-free hydantoinase process: screening for expression optimization and one-step purification as well as immobilization of hydantoinase and carbamoylase

The hydantoinase process is applied for the industrial synthesis of optically pure amino acids via whole cell biocatalysis, providing a simple and well-established method to obtain the catalyst. Nevertheless, whole cell approaches also bear disadvantages like intracellular degradation reactions, transport limitations as well as low substrate solubility. In this work the ...

Scorpion neurotoxin AaIT-expressing Beauveria bassiana enhances the virulence against Aedes albopictus mosquitoes

To improve the insecticidal efficacy of this entomopathogen Beauveria bassiana, the fungus was genetically modified to express an insect-specific scorpion neurotoxin AaIT. The virulence of the recombinant B. bassiana strain (Bb-AaIT) against Aedes albopictus adults (which occurs via penetration through the cuticle during spore germination or by conidia ingestion), and the larvae ...

A novel rhamnolipid-producing Pseudomonas aeruginosa ZS1 isolate derived from petroleum sludge suitable for bioremediation

Petroleum pollutants emulsified by biosurfactants facilitate uptake and biodegradation by environmental microbes. In this report, we show the characterization of an indigenous surfactant-producing crude-oil-eating microbe isolated from petroleum-sludge in Zhoushan islands, China, where one of the national strategic petroleum reservoirs is located. We examined biosurfactant ...

Evaluation of brewers’ spent grain as a novel media for yeast growth

Brewers’ spent grain (BSG) is a by-product generated from the beer manufacturing industry, which is extremely rich in protein and fiber. Here we use low cost BSG as the raw material for the production of a novel growth media, through a bioconversion process utilizing a food grade fungi to hydrolyze BSG. The novel fermentation media was tested on the yeast Rhodosporidium toruloides, ...

In vitro antimicrobial potential of extracts and phytoconstituents from Gymnema sylvestre R.Br. leaves and their biosafety evaluation

The in vitro antimicrobial screening of Gymnema sylvestre leaves against 13 test pathogens established its broad spectrum activity with average inhibition zone ranging from 14 to 23 mm. The antimicrobial activity of the classically- optimized aqueous extract was enhanced up to 1.45 folds, when subjected to statistical optimization using Response Surface Methodology (RSM) and was ...

Assessment of changes in the content of anthocyanins, phenolic acids, and antioxidant property of Saccharomyces cerevisiae mediated fermented black rice bran

Studies on phytochemical properties and bioactivities of rice bran revealed the wealth of natural complex antioxidant compounds. The composition and the properties of the rice bran get altered after fermentation by several microbes. This study was designed to optimize the black rice bran fermentation conditions for the total anthocyanin (ACN) content, total antioxidant properties, ...

Expanding the range of polyhydroxyalkanoates synthesized by methanotrophic bacteria through the utilization of omega-hydroxyalkanoate co-substrates

The first methanotrophic syntheses of polyhydroxyalkanoates (PHAs) that contain repeating units beyond 3-hydroxybutyrate and 3-hydroxyvalerate are reported. New PHAs synthesized by methanotrophs include poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P(3HB-co-4HB)), poly(3-hydroxybutyrate-co-5-hydroxyvalerate-co-3-hydroxyvalerate) (P(3HB-co-5HV-co-3HV)), and ...

Comparative metabolomics in vanilla pod and vanilla bean revealing the biosynthesis of vanillin during the curing process of vanilla

High-performance liquid chromatography–mass spectrometry (LC–MS) was used for comprehensive metabolomic fingerprinting of vanilla fruits prepared from the curing process. In this study, the metabolic changes of vanilla pods and vanilla beans were characterized using MS-based metabolomics to elucidate the biosynthesis of vanillin. The vanilla pods were significantly different from ...

Investigation into the antimicrobial action and mechanism of a novel endogenous peptide β-casein 197 from human milk

A novel endogenous peptide cleaved from 197–213 AA of β-casein, named β-casein 197, was identified by tandem mass spectrometry. β-casein 197 constituted a significant proportion of the peptide content in preterm milk. This study investigated the antibacterial effects and mechanisms against common pathogenic bacteria. Six bacterial strains were selected for this study: Escherichia ...

A novel anti-CD22 scFv–apoptin fusion protein induces apoptosis in malignant B-cells

CD22 marker is a highly internalizing antigen which is located on the surface of B-cells and is being used as a promising target for treatment of B cell malignancies. Monoclonal antibodies targeting CD22 have been introduced and some are currently under investigation in clinical trials. Building on the success of antibody drug conjugates, we developed a fusion protein consisting of ...

A novel constructed SPT15 mutagenesis library of Saccharomyces cerevisiae by using gTME technique for enhanced ethanol production

During the last few years, the global transcription machinery engineering (gTME) technique has gained more attention as an effective approach for the construction of novel mutants. Genetic strategies (molecular biology methods) were utilized to get mutational for both genes (SPT15 and TAF23) basically existed in the Saccharomyces cerevisiae genome via screening the gTME approach in ...

The impact of DO and salinity on microbial community in poly(butylene succinate) denitrification reactors for recirculating aquaculture system wastewater treatment

The interactions between environmental factors and bacterial community shift in solid-phase denitrification are crucial for optimum operation of a reactor and to achieve maximum treatment efficiency. In this study, Illumina high-throughput sequencing was applied to reveal the effects of different operational conditions on bacterial community distribution of three continuous ...

Degradation of aflatoxin B1 from naturally contaminated maize using the edible fungus Pleurotus ostreatus

Aflatoxins are highly carcinogenic secondary metabolites that can contaminate approximately 25% of crops and that cause or exacerbate multiple adverse health conditions, especially in Sub-Saharan Africa and South and Southeast Asia. Regulation and decontamination of aflatoxins in high exposure areas is lacking. Biological detoxification methods are promising because they are ...

Hydrogen-rich water alleviates the toxicities of different stresses to mycelial growth in Hypsizygus marmoreus

In plants, hydrogen gas (H2) enhances tolerance to several abiotic stresses, including salinity and heavy metals. However, the effect of H2 on fungal growth under different stresses remains largely unclear. In this study, hydrogen-rich water (HRW) was employed to characterize physiological roles and molecular mechanisms of H2 in the alleviation of three different stresses in ...

Characterisation and antimicrobial activity of biosurfactant extracts produced by Bacillus amyloliquefaciens and Pseudomonas aeruginosa isolated from a wastewater treatment plant

Biosurfactants are unique secondary metabolites, synthesised non-ribosomally by certain bacteria, fungi and yeast, with their most promising applications as antimicrobial agents and surfactants in the medical and food industries. Naturally produced glycolipids and lipopeptides are found as a mixture of congeners, which increases their antimicrobial potency. Sensitive analysis ...

Variants of lipopeptides and glycolipids produced by Bacillus amyloliquefaciens and Pseudomonas aeruginosa cultured in different carbon substrates

The quantitative and qualitative effect of water immiscible and miscible carbon-rich substrates on the production of biosurfactants, surfactin and rhamnolipids, by Bacillus amyloliquefaciens ST34 and Pseudomonas aeruginosa ST5, respectively, was analysed. A small-scale high throughput 96 deep-well micro-culture method was utilised to cultivate the two strains in mineral salt medium ...

PGPR strain Paenibacillus polymyxa SQR-21 potentially benefits watermelon growth by re-shaping root protein expression

Paenibacillus polymyxa (SQR-21) is not only a plant growth-promoting rhizobacteria, but also an effective biocontrol agent against Fusarium wilt disease of watermelon. For the better understanding and clarifying the potential mechanisms of SQR-21 to improve watermelon growth and disease resistance, a split-root methodology in hydroponic and LC–MS technology with the label free ...

Metabolic engineering of Escherichia coli to high efficient synthesis phenylacetic acid from phenylalanine

Phenylacetic acid (PAA) is a fine chemical with a high industrial demand for its widespread uses. Whereas, microorganic synthesis of PAA is impeded by the formation of by-product phenethyl alcohol due to quick, endogenous, and superfluous conversion of aldehydes to their corresponding alcohols, which resulted in less conversation of PAA from aldehydes. In this study, an Escherichia ...

Production of a potential liquid plant bio-stimulant by immobilized Piriformospora indica in repeated-batch fermentation process

Piriformospora indica, a mycorrhizal-like fungus able to establish associations with roots of a wide range of plants, supporting plant nutrition and increasing plant resistance and tolerance to stress, was shown to solubilise phosphate applied in the form of animal bone char (HABO) in fermentation systems. The process of P solubilisation was caused most likely by proton extrusion ...

Identification of diacetonamine from soybean curd residue as a sporulation-inducing factor toward Bacillus spp.

Under bioassay-guided investigation, a sporulation-inducing factor (SIF) toward Bacillus spp. was searched for in methanol (MeOH) extracts of soybean curd residues, and diacetonamine (1) was identified as the active compound. SIF was first isolated as a monoacetylated derivative (2, 4.1 mg from 655 g soybean curd residues), and its chemical structure was elucidated by field ...

Thermostabilization of the uronate dehydrogenase from Agrobacterium tumefaciens by semi-rational design

Aldaric acids represent biobased ‘top value-added chemicals’ that have the potential to substitute petroleum-derived chemicals. Until today they are mostly produced from corresponding aldoses using strong chemical oxidizing agents. An environmentally friendly and more selective process could be achieved by using natural resources such as seaweed or pectin as raw material. These ...

Microbicidal activity of N-chlorotaurine in combination with hydrogen peroxide

N-chlorotaurine (NCT) and hydrogen peroxide are powerful endogenous antiseptics. In vivo, the reaction between hydrogen peroxide and metal ions leads to the formation of free hydroxyl radicals, which have an increased bactericidal activity. This study examined whether there is an additive antimicrobial effect of NCT combined with hydrogen peroxide. Additionally, it was tested if ...

Mannan endo-1,4-β-mannosidase from Kitasatospora sp. isolated in Indonesia and its potential for production of mannooligosaccharides from mannan polymers

Mannan endo-1,4-β-mannosidase (commonly known as β-mannanase) catalyzes a random cleavage of the β-d-1,4-mannopyranosyl linkage in mannan polymers. The enzyme has been utilized in biofuel production from lignocellulose biomass, as well as in production of mannooligosaccharides (MOS) for applications in feed and food industries. We aimed to obtain a β-mannanase, for such mannan ...