Chlorinated nitroaromatic compounds (CNAs) are persistent environmental pollutants that have been introduced into the environment due to the anthropogenic activities. Bacteria that utilize CNAs as the sole sources of carbon and energy have been isolated from different contaminated and non-contaminated sites. Microbial metabolism of CNAs has been studied, and several metabolic pathways for degradation of CNAs have been proposed. Detoxification and biotransformation of CNAs have also been studied in various fungi, actinomycetes and bacteria. Several physicochemical methods have been used for treatment of wastewater containing CNAs; however, these methods are not suitable for in situ bioremediation. This review describes the current scenario of the degradation of CNAs.

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Arcobacter anaerophilus sp. nov., isolated from an estuarine sediment and emended description of the genus Arcobacter Two strains (JC83, JC84 T ) of obligately anaerobic, H 2 S-producing bacteria were isolated from estuarine sediment samples collected from Gangasagar, West Bengal, India. Cells were Gramstain-negative, non-motile rods. Both strains were positive for oxidase, negative for catalase, hydrolysed casein, reduced nitrate and utilized citrate. Both strains grew chemoorganoheterotrophically with optimal pH of 7-8 (range 7-10) and at 30 6C (range 25-37 6C). C 16 : 1 v7c, C 18 : 1 v7c, C 16 : 0 and C 12 : 0 were the major fatty acids of both strains with minor amounts of C 14 : 0 , C 12 : 0 3-OH and C 18 : 0 . Polar lipids of both strains included diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylserine, phosphatidylcholine, phosphatidylinositol, an unidentified aminolipid (AL2), an unidentified phospholipid (PL2) and an unidentified lipid (L3). MK-6 was the major respiratory quinone. The DNA G+C content of strains JC83 and JC84 T was 25.0 and 24.6 mol%, respectively. The strains showed DNA reassociation .85 % (86.0±0.5 %) (based on DNA-DNA hybridization). Based on 16S rRNA gene sequence analysis, both strains were identified as belonging to the family Campylobacteraceae of the class Epsilonproteobacteria with Arcobacter marinus CL-S1 T (95.4 % sequence similarity) as their closest phylogenetic neighbour. On the basis of morphological, physiological and chemotaxonomic characteristics as well as phylogenetic analysis, strains JC83 and JC84 T are considered to represent a novel species, for which the name Arcobacter anaerophilus sp. nov. is proposed. The type strain is JC84 T (5KCTC 15071 T 5MTCC 10956 T 5DSM 24636 T ). An emended description of the genus Arcobacter is provided.

Pyrazines are a group of 1,4 dinitrogen substituted benzenes. They have near ubiquitous biological distribution and majority are anthropogenic. The demand for pyrazines in the recent years has increased owing to their vast applications in the field of food, agriculture and medicine. They are widely distributed in plants, animals and microorganisms. Pyrazines are synthesized and degraded by a few bacteria and fungi. Microbial transformation of many pyrazines aided in the synthesis of several novel molecules. This review discusses the microbial metabolism of pyrazines.

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An oval to rod-shaped, phototrophic, purple non-sulfur bacterium, strain JA192 T , was isolated from an enrichment culture of a pasteurized rhizosphere soil sample from a field cultivated with jowar (sorghum) collected from Godumakunta village near Hyderabad, India. Strain JA192 T is Gram-negative, motile and produces endospores. Phylogenetic analysis on the basis of 16S rRNA gene sequences showed that the strain JA192 T is closely related to Rhodobacter sphaeroides 2.4.1 T (99.9 % sequence similarity), Rba. megalophilus JA194 T (99.8 %) and Rba. azotoformans KA25 T (98.1 %) and clusters with other species of the genus Rhodobacter of the family Rhodobacteraceae. However, DNA-DNA hybridization with Rba. sphaeroides DSM 158 T , Rba. megalophilus JA194 T and Rba. azotoformans JCM 9340 T showed relatedness of only 38-57 % with respect to strain JA192 T . On the basis of 16S rRNA gene sequence analysis, DNA-DNA hybridization data and morphological, physiological and chemotaxonomic characters, strain JA192 T represents a novel species of the genus Rhodobacter, for which the name Rhodobacter johrii sp. nov. is proposed. The type strain is JA192 T (5DSM 18678 T 5JCM 14543 T 5MTCC 8172 T ).

Strain JC164(T) was isolated from a water sample from a rice field at Jamdih, Mau, Uttar Pradesh, India. Colonies of strain JC164(T) were brown-yellow and cells were Gram-stain-negative. Catalase, oxidase and amylase were present. iso-C(15:0), iso-C(16:0), iso-C15 1 G, iso-C(15:0) 3-OH and iso-C(14:0) were the predominant fatty acids with minor amounts of iso-C(16:0) 3-OH, anteiso-C(15:0), C(16:0), iso-C(16:1) H, iso-C(14:0) 3-OH and iso-C(13:0). Strain JC164(T) contained phosphatidylethanolamine and a few unidentified lipids (L1, L3 and L6) as major polar lipids. Bacteriohopane derivative 1 (BHD1) and diplopterol (DPL) were the major hopanoids. β-Carotene was one among the several spirilloxanthin series carotenoids present in strain JC164(T). Genomic DNA G+C content was 39.6 mol%. 16S rRNA gene sequence comparisons indicated that strain JC164(T) represents a member of the genus Flavobacterium (family Flavobacteriaceae, class Flavobacteriia). The most closely related taxa to strain JC164(T) were Flavobacterium sasangense YC6274(T) (98.5%), Flavobacterium cucumis R2A45-3(T) (98.1%), Flavobacterium cheniae NJ-26(T) (97.2%) and the novel strain possessed <95.1% sequence similarity with other members of the genus Flavobacterium. However, strain JC164(T) showed 12.5 ± 2, 13.6 ± 1 and 17.4 ± 2% genomic DNA association (based on DNA-DNA hybridization) with Flavobacterium sasangense KCTC 22246(T), Flavobacterium cucumis DSM 18830(T) and Flavobacterium cheniae CGMCC 1.6844(T), respectively. The distinct genomic difference and morphological, physiological and chemotaxonomic differences from the previously described taxa support the classification of strain JC164(T) as a representative of a novel species of the genus Flavobacterium, for which the name Flavobacterium aquaticum sp. nov. is proposed. The type strain is JC164(T) ( = KCTC 32196(T) = CGMCC 1.12398=LMG 27251(T)).