Research Publications (Food Safety)

Environment and food contamination with cadmium (Cd) can cause serious toxicity, posing a severe threat to agricultural production and human health. However, how amino acids contribute to defenses against oxidative stress caused by Cd in cells is not fully understood. As a model eukaryote with a relatively clear genetic background, Saccharomyces cerevisiae has been commonly used in Cd toxicity research.

A bacterium designated as strain STP14 was isolated from a sewage treatment plant and identified as Acinetobacter calcoaceticus based on 16S ribosomal RNA gene sequencing. Strain STP14 exhibited resistance to several metals such as mercury, cobalt, copper, nickel, lead, and cadmium. Among these metals, the bacterium showed maximum resistance to cadmium in concentration up to 1200 mg/L. The antimicrobial susceptibility test of A.

Enterobacter tabaci 4M9 (CCB‐MBL 5004) was reported to have plant growth‐promoting and heavy metal tolerance traits. It was able to tolerate more than 300 mg/L Cd, 600 mg/L As, and 500 mg/L Pb and still maintained the ability to produce plant growth‐promoting substances under metal stress conditions. To explore the genetic basis of these beneficial traits, the complete genome sequencing of 4M9 was carried out using Pacific Bioscience (PacBio) sequencing technology.

Salmonella enterica serovar Typhimurium (S. Typhimurium) is exposed to biotic and abiotic stresses. The survival of Salmonella in nature depends on the global regulators like cAMP receptor protein (CRP). The role of CRP in the phenotypic characteristics and stress tolerance was elucidated in S. Typhimurium using a crp gene null mutant (Δcrp).

In Aspergillus nidulans, there are two putative glycerol 3‐phosphate dehydrogenases encoded by the genes gfdA and gfdB, while the genome of the osmophilic Aspergillus glaucus harbors only the ortholog of the A. nidulans gfdA gene. Our aim was to insert the gfdB gene into the genome of A. glaucus, and we reached this goal with the adaptation of the Agrobacterium tumefaciens‐mediated transformation method. We tested the growth of the gfdB‐complemented A.

The P‐type ATPase CrpA is an important Cu2+/Cd2+ pump in the Aspergilli, significantly contributing to the heavy metal stress tolerance of these ascomycetous fungi. As expected, the deletion of crpA resulted in Cu2+/Cd2+‐sensitive phenotypes in Aspergillus nidulans on stress agar plates inoculated with conidia.

Bacitracin is one of the most important antibiotics used in different biomedical fields. It helps to achieve sizeable amount of foreign exchange due to its use in the poultry feed. The cheap agricultural wastes are readily available for the preparation of fermentation media used for bacitracin production. The microorganisms could be mutated with different chemicals and UV radiation to improve bacitracin production.

This study was carried out to investigate the possible efflux pump inhibitory activity of biologically synthesized silver nanoparticles (AgNPs) against multidrug‐resistant (MDR) Acinetobacter baumannii isolates. In this study, the physicochemical characteristics of synthesized AgNPs were investigated using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X‐ray diffraction (XRD), and Fourier transform infrared spectrophotometer (FTIR) methods. Subsequently, MDR A.

Although highly accurate molecular processes and various messenger RNA (mRNA) quality control and ribosome proofreading mechanisms are used by organisms to transcribe their genes and maintain the fidelity of genetic information, errors are inherent in all biological systems. Low‐level translation errors caused by an imbalance of homologous and nonhomologous amino acids caused by stress conditions are particularly common.

A study was conducted to examine the prevalence of brucellosis (in animal farms) in the vicinity of Islamabad and Rawalpindi. A total of 170 milk samples were collected randomly from several farmhouses. The collected milk samples were initially screened by a Brucella selective medium. The bacterial isolates grown on the selective medium were subjected to biochemical identification for further confirmation of Brucella species.

The growth of technology and requirements globally for various commodities has brought about new challenges. Biofilms are aggregations of microbial cells, which contaminate and spoil industrial components and environments. These microbial cells with extracellular polymeric substances colonize living and nonliving surfaces and pose a serious problem for all industries, affecting their processes, leading to a reduction of product quality and economic loss.

Salmonella Enteritidis is an important foodborne pathogen that can infect a wide range of animal species including human beings, resulting in great losses to commercial husbandry and human health. CirA is an outer membrane receptor involved in iron uptake and colicin1A/B‐mediated competitive killing. Although iron uptake is crucial to bacterial virulence, limited literature is available about the role of CirA in infection. In the present work, we aimed to evaluate the role of CirA during S.

Transcriptional regulator GntR controls diverse physiological functions necessary for Brucella survival. In the intracellular pathogen Brucella, GntR has been shown to regulate the expression of genes related to virulence. However, the precise determination of GntR direct targets has so far proved elusive. Therefore, we performed chromatin immunoprecipitation of GntR10 followed by next‐generation sequencing (ChIP‐seq).

Metals are among the most prevalent pollutants released into the environment. For these reasons, the use of biomarkers for environmental monitoring of individuals and populations exposed to metal pollution has gained considerable attention, offering fast and sensitive detection of chemical stress in organisms.

The current research focuses on anaerobic respiration of arsenic and other toxic metals by purple nonsulfur bacteria (PNSB). Among the optimization assays performed were carbon utilization, cross metal resistance, and metal respiration, along with a comparison of each assay in photoheterotrophic and chemoheterotrophic growth. The bacteria were identified by the classification of 16S ribosomal RNA gene sequences. Rhodobacter sp.

Salmonella enterica serovar Typhimurium (S. Tm) is a major intracellular pathogen that infects humans and animals, and its survival and growth in macrophages is essential for its pathogenicity. More than 50 putative regulatory proteins are encoded by the S. Tm genome, but the functions of these regulatory proteins in mediating S. Tm pathogenicity are largely unknown.

In the current study, psychrophilic, endolithic, and epilithic bacterial strains were isolated and characterized from the nonpolar Laohugou glacier (LHG) no. 12, the largest valley glacier in the western Qilian Mts. located on the northeastern edge of the Tibetan Plateau. Five different types of samples, rocks, soil, glacial water, ice/snow, and cryoconite, were collected. A total of 48 bacterial strains were isolated by using the R2A bacterial cultural medium.

The yigP (ubiJ) locus has been shown to be associated with many phenotypic changes in Escherichia coli, while the individual function of its two products, EsrE small RNA and UbiJ protein, is still elusive. In this study, we constructed two single‐element mutants, EsrE mutant strain Mut and UbiJ mutant strain Ter, on the basis of the base substitution programs.

Quorum sensing (QS)‐mediated biofilm‐forming rhizobacteria are indispensable due to their competitiveness in the crop rhizosphere. In the present work, we have reported on the occurrence of diversified bacterial species capable of producing N‐acyl homoserine lactone (AHL) as the QS signal in the roots of a rice plant grown under field conditions.

The aim of this study was to identify and characterize the SE‐P3, P16, P37, and P47 phages infecting Salmonella Enteritidis. Transmission electron microscopy analysis showed that the SE phages belonged to the Myoviridae or Siphoviridae family and had plaque sizes between 0.622 ± 0.027 and 1.630 ± 0.036 mm in diameter. sefC, pefA, spvC, sopE, and gipA virulent gene regions were absent in their genome and their calculated genome sizes were between 35.9 and 37.8 kbp.

The aim of this study was to examine four strains of two yeast species in relation to their capability for assimilating alkanes in the presence of heavy metals (HMs). The four strains tested were Candida pseudoglaebosa ENCB‐7 and Kodamaea ohmeri ENCB‐8R, ENCB‐23, and ENCB‐VIK. Determination was made of the expression of CYP52 genes involved in alkane hydroxylation.

This study investigates the effect of metals (cadmium, lead, mercury, and tellurium) and organic pollutants (benzene, diesel, lindane, and xylene) on a dinoflagellate—Prorocentrum sigmoides Böhm—and its associated culturable bacteria. Two bacterial cultures (Bacillus subtilis strain PD005 and B. xiamensis strain PD006) were isolated from P. sigmoides and characterized by scanning electron microscopy, 16S ribosomal RNA sequencing, biochemical analyses, and growth curve studies.

Heavy metals such as lead, chromium, and metalloid like arsenic dominate the pinnacle in posing a threat to life. Being environment‐friendly, elucidating the mechanism by which microorganisms detoxify such elements has always been an active field of research hitherto. In the present study, we have investigated the capability of nitrogen‐deprived Papiliotrema laurentii strain RY1 toward enhanced tolerance and neutralizing toxic elements.

Metallothionein (MT) is a low‐molecular‐weight protein with a high metal binding capacity and plays a key role in organism adaptation to heavy metals. In this study, a metallothionein gene was successfully cloned and sequenced from Antarctic sea‐ice yeast Rhodotorula mucilaginosa AN5. Nucleotide sequencing and analysis revealed that the gene had four exons interrupted by three introns.

Removal of heavy metals from food material by growing micro‐organisms is limited by the toxicity to cells. In this study, different preincubation treatments were investigated to analyze their effects on cadmium resistance and removal ability of Pichia kudriavzevii A16 and Saccharomyces cerevisiae CICC1211. Sucrose preincubation improved the cadmium resistance of both yeast cells and increased the cadmium‐removal rate of P. kudriavzevii A16.