Current Genomics - Volume 21, Issue 2, 2020

Agri-food waste biomass is the most abundant organic waste and has high valorisation potential for sustainable bioproducts development. These wastes are not only recyclable in nature but are also rich sources of bioactive carbohydrates, peptides, pigments, polyphenols, vitamins, natural antioxidants, etc. Bioconversion of agri-food waste to value-added products is very important towards zero waste and circular economy concepts. To reduce the environmental burden, food researchers are seeking strategies to utilize this waste for microbial pigments production and further biotechnological exploitation in functional foods or value-added products. Microbes are valuable sources for a range of bioactive molecules, including microbial pigments production through fermentation and/or utilisation of waste. Here, we have reviewed some of the recent advancements made in important bioengineering technologies to develop engineered microbial systems for enhanced pigments production using agrifood wastes biomass/by-products as substrates in a sustainable way.

The concurrence of microorganisms in niches that are hostile like extremes of temperature, pH, salt concentration and high pressure depends upon novel molecular mechanisms to enhance the stability of their proteins, nucleic acids, lipids and cell membranes. The structural, physiological and genomic features of extremophiles that make them capable of withstanding extremely selective environmental conditions are particularly fascinating. Highly stable enzymes exhibiting several industrial and biotechnological properties are being isolated and purified from these extremophiles. Successful gene cloning of the purified extremozymes in the mesophilic hosts has already been done. Various extremozymes such as amylase, lipase, xylanase, cellulase and protease from thermophiles, halothermophiles and psychrophiles are of industrial interests due to their enhanced stability at forbidding conditions. In this review, we made an attempt to point out the unique features of extremophiles, particularly thermophiles and psychrophiles, at the structural, genomic and proteomic levels, which allow for functionality at harsh conditions focusing on the temperature tolerance by them.

Background: Petroleum polycyclic aromatic hydrocarbons (PAHs) are known to be toxic and carcinogenic for humans and their contamination of soils and water is of great environmental concern. Identification of the key microorganisms that play a role in pollutant degradation processes is relevant to the development of optimal in situ bioremediation strategies. Objective: Detection of the ability of Pseudomonas fluorescens AH-40 to consume phenanthrene as a sole carbon source and determining the variation in the concentration of both nahAC and C23O catabolic genes during 15 days of the incubation period. Methods: In the current study, a bacterial strain AH-40 was isolated from crude oil polluted soil by enrichment technique in mineral basal salts (MBS) medium supplemented with phenanthrene (PAH) as a sole carbon and energy source. The isolated strain was genetically identified based on 16S rDNA sequence analysis. The degradation of PAHs by this strain was confirmed by HPLC analysis. The detection and quantification of naphthalene dioxygenase (nahAc) and catechol 2,3-dioxygenase (C23O) genes, which play a critical role during the mineralization of PAHs in the liquid bacterial culture were achieved by quantitative PCR. Results: Strain AH-40 was identified as pseudomonas fluorescens. It degraded 97% of 150 mg phenanthrene L-1 within 15 days, which is faster than previously reported pure cultures. The copy numbers of chromosomal encoding catabolic genes nahAc and C23O increased during the process of phenanthrene degradation. Conclusion: nahAc and C23O genes are the main marker genes for phenanthrene degradation by strain AH-40. P. fluorescence AH-40 could be recommended for bioremediation of phenanthrene contaminated site.

Background: Pancreatic ductal adenocarcinoma (PDAC) is associated with poor prognosis. In this context, the identification of biomarkers regarding the PDAC diagnosis, monitoring, and prognosis is crucial. Objectives: The purpose of the current study was to investigate the differential gene expression profile of the chloride intracellular channel (CLIC) gene family network in patients with PDAC, in order to suggest novel biomarkers. Methods: In silico techniques were used to construct the interactome of the CLIC gene family, identify the differentially expressed genes (DEGs) in PDAC as compared to healthy controls, and evaluate their potential prognostic role. Results: Transcriptomic data of three microarray datasets were included, incorporating 114 tumor and 59 normal pancreatic samples. Twenty DEGs were identified; eight were up-regulated and twelve were downregulated. A molecular signature of seven genes (Chloride Intracellular Channel 1 – CLIC1; Chloride Intracellular Channel 3 – CLIC3; Chloride Intracellular Channel 4 – CLIC4; Ganglioside Induced Differentiation Associated Protein 1 – GDAP1; Ganglioside Induced Differentiation Associated Protein 1 Like 1 – GDAP1L1; Glutathione S-Transferase Pi 1 - GSTP1; Prostaglandin E Synthase 2 – PTGES2) were identified as prognostic markers associated with overall survival. Positive correlations were reported regarding the expression of CLIC1-CLIC3, CLIC4-CLIC5, and CLIC5- CLIC6. Finally, gene set enrichment analysis demonstrated the molecular functions and miRNA families (hsa-miR-122, hsa-miR-618, hsa-miR-425, and hsa-miR-518) relevant to the seven prognostic markers. Conclusion: These outcomes demonstrate a seven-gene molecular panel that predicts the patients’ prospective survival following pancreatic resection for PDAC.

Background: Staphylococcus aureus isolates expressing the Panton-Valentine Leukocidin (PVL) have been related to a wide range of diseases. Recently, pvl-positive community-associated methicillin-resistant S. aureus belonging to USA1100 (ST30/CC30/SCCmec IV) lineage has emerged in Brazilian hospitals. Objective: The aim of this work was to sequence the genome of a pvl-positive USA1100 Vancomycin- Intermediate-Resistant S. aureus (VISA) isolate from Rio de Janeiro, Brazil. Methods: The 13420 genome was sequenced using the HiSeq 2500 platform. The draft genome, plasmids annotation, and genome analysis were performed using RAST. Comparison of the relative pvl gene expression of six S. aureus isolates was performed by qRT-PCR. Results: The isolate presented the ΦPVL phage codifying for the H2b PVL protein isoform, and another prophage carrying a PVL variant named lukF and lukS-PV.2. The 13420 genome presented a high number of virulence determinants, such as genes codifying for serine-protease proteins, enterotoxins (egc), the immune evasion cluster (IEC), adhesion proteins, spermine/spermidine acetyltransferase gene (blt), superantigen-like proteins, as well as the ica operon. Point mutations at vraS, tcaA, and tcaB genes were detected. Moreover, the PVL mRNA relative expression of the 13420 isolate was five times higher than mRNA PVL levels of the USA300/ST8 reference strain. Conclusion: We described for the first time the genome sequence of a VISA isolate harboring two pvl-associated genes and other virulence factors that may improve the USA1100/ST30 lineage fitness and impact its pathogenicity and spreading at Brazilian hospitals.

Background: Large scale cultivation of sorghum for food, feed, and biofuel requires concerted efforts for engineering multipurpose cultivars with optimised agronomic traits. Due to their vital role in regulating the biosynthesis of phenylpropanoid-derived compounds, biomass composition, biotic, and abiotic stress response, R2R3-MYB family transcription factors are ideal targets for improving environmental resilience and economic value of sorghum. Methods: We used diverse computational biology tools to survey the sorghum genome to identify R2R3-MYB transcription factors followed by their structural and phylogenomic analysis. We used inhouse generated as well as publicly available high throughput expression data to analyse the R2R3 expression patterns in various sorghum tissue types. Results: We have identified a total of 134 R2R3-MYB genes from sorghum and developed a framework to predict gene functions. Collating information from the physical location, duplication, structural analysis, orthologous sequences, phylogeny, and expression patterns revealed the role of duplications in clade-wise expansion of the R2R3-MYB family as well as intra-clade functional diversification. Using publicly available and in-house generated RNA sequencing data, we provide MYB candidates for conditioning biofuel syndrome by engineering phenylpropanoid biosynthesis and sugar signalling pathways in sorghum. Conclusion: The results presented here are pivotal to prioritize MYB genes for functional validation and optimize agronomic traits in sorghum.