Aromatic compounds are among the most prevalent and persistent pollutants in the environment. Petroleum-contaminated soil and sediment commonly contain a mixture of polycyclic aromatic hydrocarbons (PAHs) and heterocyclic aromatics. Aromatics derived from industrial activities often have functional groups such as alkyls, halogens and nitro groups. Biodegradation is a major mechanism of removal of organic pollutants from a contaminated site. This review focuses on bacterial degradation pathways of selected aromatic compounds. Catabolic pathways of naphthalene, fluorene, phenanthrene, fluoranthene, pyrene, and benzo[a]pyrene are described in detail. Bacterial catabolism of the heterocycles dibenzofuran, carbazole, dibenzothiophene, and dibenzodioxin is discussed. Bacterial catabolism of alkylated PAHs is summarized, followed by a brief discussion of proteomics and metabolomics as powerful tools for elucidation of biodegradation mechanisms.

Moringa oleifera Lam., also known as the ‘drumstick tree,’ is recognized as a vibrant and affordable source of phytochemicals, having potential applications in medicines, functional food preparations, water purification, and biodiesel production. The multiple biological activities including antiproliferation, hepatoprotective, anti-inflammatory, antinociceptive, antiatherosclerotic, oxidative DNA damage protective, antiperoxidative, cardioprotective, as well as folk medicinal uses of M. oleifera (MO) are attributed to the presence of functional bioactive compounds, such as phenolic acids, flavonoids, alkaloids, phytosterols, natural sugars, vitamins, minerals, and organic acids. The low molecular weight of M. oleifera cationic proteins (MOCP) extracted from the seeds is very useful and is used in water purification, because of its potent antimicrobial and coagulant properties. Also, the M. oleifera methyl esters (MOME) produced from the oil of the seeds meet the major specifications of the biodiesel standard of Germany, Europe, and United States (US). Thus, MO is emerging as one of the prominent industrial crops for sustainable biodiesel production in tropical and subtropical countries. In view of the high nutritional, nutraceutical, and industrial values, it is important to compile an updated comprehensive review on the related aspects of this multipurpose and miracle tree. Hence, the present study is focused on the nutritionally significant bioactives and medicinal and biological properties, to explore the potential applications of MO in nutritionally rich food preparations. Furthermore, water coagulation, proteins, and fatty acid methyl esters from the MO seeds are reviewed, to explore their possible industrial applications in biodiesel production and water purification. In addition, the future perspectives in these areas are suggested.

We report the complete genome sequence of the deep-sea ␥-proteobacterium, Idiomarina loihiensis, isolated recently from a hydrothermal vent at 1,300-m depth on the Lo ihi submarine volcano, Hawaii. The I. loihiensis genome comprises a single chromosome of 2,839,318 base pairs, encoding 2,640 proteins, four rRNA operons, and 56 tRNA genes. A comparison of I. loihiensis to the genomes of other ␥-proteobacteria reveals abundance of amino acid transport and degradation enzymes, but a loss of sugar transport systems and certain enzymes of sugar metabolism. This finding suggests that I. loihiensis relies primarily on amino acid catabolism, rather than on sugar fermentation, for carbon and energy. Enzymes for biosynthesis of purines, pyrimidines, the majority of amino acids, and coenzymes are encoded in the genome, but biosynthetic pathways for Leu, Ile, Val, Thr, and Met are incomplete. Auxotrophy for Val and Thr was confirmed by in vivo experiments. The I. loihiensis genome contains a cluster of 32 genes encoding enzymes for exopolysaccharide and capsular polysaccharide synthesis. It also encodes diverse peptidases, a variety of peptide and amino acid uptake systems, and versatile signal transduction machinery. We propose that the source of amino acids for I. loihiensis growth are the proteinaceous particles present in the deep sea hydrothermal vent waters. I. loihiensis would colonize these particles by using the secreted exopolysaccharide, digest these proteins, and metabolize the resulting peptides and amino acids. In summary, the I. loihiensis genome reveals an integrated mechanism of metabolic adaptation to the constantly changing deep-sea hydrothermal ecosystem.hydrothermal vent