Hexachlorocyclohexane-contaminated Soil Research Articles

Draft Genome Sequence of Fusarium equiseti K3, a Fungal Species Isolated from Hexachlorocyclohexane-Contaminated Soil.

ABSTRACTWe present the draft genome sequence of Fusarium equiseti strain K3, a fungus isolated from a hexachlorocyclohexane (HCH)-contaminated soil (Kitengela, Kenya). The 37.88-Mb draft genome sequence consists of 206 contigs, 12,311 predicted protein-coding sequences, and 261 tRNA sequences. This genome sequence contributes to our understanding of fungal-bacterial interactions during hexachlorocyclohexane degradation.

Corynebacteriumpollutisoli sp. nov., isolated from hexachlorocyclohexane-contaminated soil.

A Gram-stain-positive, alkaliphilic, non-spore-forming, non-motile bacterium, designated VDS11T, was isolated from a soil sample collected from the hexachlorocyclohexane dumpsite, located at Ummari Village, Lucknow, Uttar Pradesh, India. 16S rRNA gene sequence analysis indicated that strain VDS11T occupies a distinct phylogenetic position within the genus Corynebacterium, showing the highest sequence similarity with Corynebacterium humireducens MFC-5T (98.7 %) and Corynebacterium nasicanis 2673/12T (98.4 %). The DNA G+C content was 50.6 mol% and the DNA-DNA hybridization (DDH) relatedness value with C. humireducens MFC-5T and C. nasicanis 2673/12T was 49.7 and 39.6 %, respectively. Strain VDS11T contained C16 : 0 (28.3), C18 : 1ω9c (52.3), C18 : 0 (1.3) and C20 : 0 (3.0) as the major cellular fatty acids. The major isoprenoid quinone was MK-9(H2). Strain VDS11T contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, unidentified aminolipids, glycolipids, phospholipids and unidentified lipids as the major polar lipids. The peptidoglycan type was A31 (meso 2, 6-diaminopimelic acid, directly cross-linked). Based on the results of DDH studies and the biochemical and physiological data, strain VDS11T represents a novel species of the genus Corynebacteriumfor which the name Corynebacterium pollutisoli sp. nov., has been proposed. The type strain is VDS11T(=DSM 100104T=MCC 2722T=KCTC 39687T).

Genome Sequence of Staphylococcus aureus Strain HUK16, Isolated from Hexachlorocyclohexane-Contaminated Soil.

Staphylococcus aureus strain HUK16 has been isolated from hexachlorocyclohexane (HCH)-long-term contaminated soil. The genome of strain HUK16 was sequenced to understand the genetic basis of its adaptation to HCH and to find the potential metabolic pathways allowing it to degrade the pesticide. Here, we report the annotated draft genome sequence (~2.7 Mbp) of this strain.

Genome Sequence of Pseudomonas sp. HUK17, Isolated from Hexachlorocyclohexane-Contaminated Soil.

Pseudomonas sp. HUK17 has been isolated from hexachlorocyclohexane (HCH) long-term contaminated soil. The genome of strain HUK17 was sequenced to elucidate its adaptation toward HCH and to evaluate the presence of pesticide degradation pathways. Here, we report the annotated draft genome sequence (~2.6 Mbp) of this strain.

Genome Sequence of Bacillus subtilis Strain HUK15, Isolated from Hexachlorocyclohexane-Contaminated Soil.

Bacillus subtilis strain HUK15 has been isolated from hexachlorocyclohexane (HCH)-long-term-contaminated soil. The genome of strain HUK15 was sequenced to investigate its adaptation toward HCH and its potential capability to degrade the pesticide. Here, we report the annotated draft genome sequence (~4.3 Mbp) of this strain.

Luteimonas tolerans sp. nov., isolated from hexachlorocyclohexane-contaminated soil.

A Gram-stain-negative, aerobic, rod-shaped, non-spore-forming, yellow pigmented bacterial strain (UM1T) was isolated from the hexachlorocyclohexane (HCH)-contaminated dumpsite located at Ummari village in Lucknow, India. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain UM1T belongs to the genus Luteimonas with Luteimonas aestuarii B9T as the closest neighbour (97.2% 16S rRNA gene sequence similarity). The DNA G+C content of strain UM1T was 64.3 mol%. The major polar lipids were diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE) and phosphatidylglycerol (PG). Main fatty acids were iso-C15:0, iso-C11:0, iso-C11:0 3-OH, iso-C17:0 and summed feature 9 (C16:0 10-methyl and/or iso-C17:1ω9c). Ubiquinone (Q-8) was the only respiratory quinone. Spermidine was detected as the major polyamine. The DNA-DNA relatedness value of strain UM1T with respect to its closest neighbour Luteimonas aestuarii B9T was well below 70 % (∼49%). Thus, data obtained from phylogenetic analysis, DNA-DNA hybridization, and chemotaxonomical and biochemical analyses supports classification of strain UM1T as representative of a novel species of the genus Luteimonas, for which the name Luteimonas tolerans sp. nov. is proposed. The type strain is UM1T (=DSM 28473T=MCC 2572T=KCTC 42936T).

Pontibacter ummariensis sp. nov., isolated from a hexachlorocyclohexane-contaminated soil.

A Gram-stain-negative, pinkish-red, rod-shaped bacterium designated strain NKM1T was isolated from soil samples contaminated with hexachlorocyclohexane isomers, collected from Ummari village, Lucknow, Uttar Pradesh, India. The strain was characterized by a polyphasic taxonomic approach. 16S rRNA gene sequence analysis showed that strain NKM1T clustered exclusively with members of the genus Pontibacter of the family Cytophagaceae, phylum Bacteroidetes. The 16S rRNA gene sequence similarity to type strains of the genus Pontibacter ranged from 96.7 to 93.8 %, with the highest sequence similarity found with Pontibacter odishensis JC130T (96.7 %). Cells of strain NKM1T were aerobic, non-flagellated and non-motile. Strain NKM1T was catalase- and oxidase-positive but negative for nitrate reduction and hydrolysis of gelatin. The major fatty acids in strain NKM1T were anteiso-C15 : 0, iso-C15 : 0, C16 : 0, C18 : 1ω9c and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c). The polar lipid profile of strain NKM1T showed the presence of phosphatidylethanolamine and unknown glycolipids as well as aminolipids. sym-Homospermidine was found to be the major polyamine and menaquinone 7 (MK-7) was the major respiratory quinone. The DNA G+C content of strain NKM1T was determined to be 58.6 mol%. Based on phenotypic, chemotaxonomic, physiological and biochemical evidence, it is proposed that isolate NKM1T represents a novel species that belongs to the genus Pontibacter, for which the name Pontibacter ummariensis sp. nov. is proposed. The type strain is NKM1T ( = DSM 100161T = KCTC 42944T = MCC 2777T).

Effect of Plant Growth Regulators on Phytoremediation of Hexachlorocyclohexane-Contaminated Soil

The influence of three plant growth regulators, indolebutyric acid (IBA), thidiazuron (TDZ) and gibberellic acid (GA3), either individually or in pair-wise combinations, on the ability of waxy corn plant to remove hexachlorocyclohexane (HCH) from contaminated soil was studied. Waxy corn seeds were immersed for 3 h in solutions of 1.0 mg/l IBA, 0.01 mg/l TDZ, 0.1 mg/l GA3, or a mixture of two of the growth regulators, and then inoculated in soil contaminated with 46.8 mg/kg HCH for 30 days. Pretreatment of corn seeds with the plant growth regulators did not enhance corn growth when compared with those immersed in distilled water (control), but the pretreatment enhanced HCH removal significantly. On day 30, HCH concentration in the bulk soil planted with corn seeds pretreated with GA3 or TDZ+GA3 decreased by 97.4% and 98.4%, respectively. In comparison, HCH removal in soil planted with non-pretreated control waxy corn seeds was only 35.7%. The effect of several growth regulator application methods was tested with 0.01 mg/l TDZ. The results showed that none of the methods, which ranged from seed immersion, watering in soil, or spraying on shoots, affected HCH removal from soil. However, the method of applying the growth regulators may affect corn growth. Watering the corn plant with TDZ in soil led to higher root fresh weight (2.2 g) and higher root dried weight (0.57 g) than the other treatments (0.2–1.7 g root fresh weight and 0.02–0.43 g root dried weight) on day 30. Varying the concentrations of GA3 did not affect the enhancement of corn growth and HCH removal on day 30. The results showed that plant growth regulators may have potential for use to enhance HCH phytoremediation.

Parapedobacter indicus sp. nov., isolated from hexachlorocyclohexane-contaminated soil.

Strain RK1(T), a Gram-stain-negative, non-spore-forming, rod-shaped, non-motile bacterium was isolated from a hexachlorocyclohexane (HCH) dumpsite, Lucknow, India. 16S rRNA gene sequence analysis revealed that strain RK1(T) belongs to the family Sphingobacteriaceae and showed highest sequence similarity to Parapedobacter koreensis Jip14(T) (95.63%). The major cellular fatty acids of strain RK1(T) were iso-C15:0, summed feature 3 (C16:1ω7c and/or C16:1ω6c), iso-C17:0 3-OH, summed feature 9 (10-methyl C16:0 and/or iso-C17:1ω9c), iso-C15:0 3-OH and C16 : 0. The major respiratory pigment and polyamine of RK1(T) were menaquinone (MK-7) and homospermidine, respectively. The main polar lipids were phosphatidylethanolamine and sphingolipid. The G+C content of the DNA was 44.5 mol%. The results of physiological and biochemical tests and 16S rRNA sequence analysis clearly demonstrated that strain RK1(T) represents a novel species of the genus Parapedobacter, for which the name Parapedobacter indicus sp. nov. is proposed. The type strain is RK1(T) ( = DSM 28470(T) =MCC 2546(T)).

Pontibacter indicus sp. nov., isolated from hexachlorocyclohexane-contaminated soil

An orange-pigmented bacterial strain, designated LP100(T), was isolated from hexachlorocyclohexane-contaminated soil (Lucknow, India). A neighbour-joining tree based on 16S rRNA gene sequences showed that strain LP100(T) occupied a distinct phylogenetic position in the Pontibacter species cluster, showing highest similarity with Pontibacter lucknowensis DM9(T) (97.4 %). Levels of similarity to strains of other Pontibacter species ranged between 94.0 and 96.8 %. Strain LP100(T) contained MK-7 as the predominant menaquinone and sym-homospermidine was the major polyamine in the cell. The major cellular fatty acids of strain LP100(T) were anteiso-C17 : 0 A, iso-C15 : 0 and iso-C18 : 1 H. The polar lipid profile of strain LP100(T) showed the presence of phosphatidylethanolamine, an unidentified aminophospholipid, three unknown aminolipids and two unknown polar lipids. The G+C content of strain LP100(T) was 58.2 mol%. The results of DNA-DNA hybridization, biochemical and physiological tests clearly distinguish the novel strain from closely related species of the genus Pontibacter. Therefore, strain LP100(T) represents a novel species of the genus Pontibacter for which the name Pontibacter indicus is proposed. The type strain is LP100(T) ( = CCM8435(T) = MCC2027(T)).

Novosphingobium barchaimii sp. nov., isolated from hexachlorocyclohexane-contaminated soil

A yellow-pigmented bacterial strain, designated LL02(T), was isolated from hexachlorocyclohexane-contaminated soil from Spolana Neratovice, a former Czech producer of lindane. A neighbour-joining tree based on 16S rRNA gene sequences showed that strain LL02(T) occupied a distinct phylogenetic position in the genus Novosphingobium and showed the highest sequence similarity with Novosphingobium resinovorum NCIMB 8767(T) (98.59 %). DNA-DNA relatedness between strain LL02(T) and its closest phylogenetic neighbours was <70 %, which indicated that strain LL02(T) represented a novel species of the genus Novosphingobium. The DNA G+C content of strain LL02(T) was 67.72±0 mol%. The major respiratory quinone was ubiquinone Q-10. The polar lipid profile of the isolate corresponded to those reported for other members of the genus Novosphingobium (phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylcholine, phosphatidylglycerol, phosphatidylmonomethylethanolamine and sphingoglycolipids), thus supporting its classification in the genus. Spermidine was the major polyamine. The major fatty acids were summed feature 3 (consisting of C(16 : 1)ω7c and/or C(16 : 1)ω6c; 40.13 %), summed feature 8 (consisting of C(18 : 1)ω7c and/or C(18 : 1)ω6c; 31.09 %) and C(14 : 0) 2-OH (23.16 %). The results obtained from DNA-DNA hybridization and biochemical and physiological tests clearly distinguished the isolate from its closest phylogenetic neighbours. Thus, strain LL02(T) represents a novel species of the genus Novosphingobium, for which the name Novosphingobium barchaimii sp. nov. is proposed. The type strain is LL02(T) ( = CCM 7980(T) = DSM 25411(T)).

Sphingobium baderi sp. nov., isolated from a hexachlorocyclohexane dump site

A Gram-stain-negative, rod-shaped and white-coloured bacterial strain, designated LL03(T), was isolated from hexachlorocyclohexane-contaminated soil at Spolana Neratovice, Czech Republic, where lindane was formerly produced. Strain LL03(T) was found to be a degrader of α-, γ- and δ-isomers of hexachlorocyclohexane, although no significant degradation activity was observed for the β-isomer. A neighbour-joining tree based on 16S rRNA gene sequences showed that strain LL03(T) occupied a distinct phylogenetic position in the Sphingobium cluster, showing the highest similarity with Sphingobium wenxiniae JZ-1(T) (99.2 %). The DNA G+C content of strain LL03(T) was 67.0 mol%. DNA-DNA relatedness values of strain LL03(T) with its close phylogenetic neighbours were below the threshold level of 70 %, supporting its identification as a representative of a novel species of the genus Sphingobium. The predominant respiratory quinone was ubiquinone Q-10. The polar lipid profile of strain LL03(T) also corresponded to those reported for other Sphingobium species (phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylcholine, phosphatidylglycerol, phosphatidylmonomethylethanolamine and sphingoglycolipid), supporting its identification as a member of the genus Sphingobium. Spermidine was identified as the major polyamine. The predominant fatty acids were 16 : 0, summed feature 3 (16 : 1ω7c and/or 16 : 1ω6c), summed feature 8 (18 : 1ω7c and/or 18 : 1ω6c) and 14 : 0 2-OH. The polar lipid pattern, the presence of spermidine and ubiquinone Q-10, the predominance of the cellular fatty acids C(18 : 1)ω7c, C(16 : 0) and C(14 : 0) 2-OH and the G+C content of the genomic DNA supported the affiliation of the strain to the genus Sphingobium. The results obtained after DNA-DNA hybridization, biochemical and physiological tests clearly distinguished it from closely related species of the genus Sphingobium. Therefore, strain LL03(T) represents a novel species of the genus Sphingobium for which the name Sphingobium baderi LL03(T) sp. nov. is proposed; the type strain is LL03(T) ( = CCM 7981(T) = DSM 25433(T)).

Flavobacterium ummariense sp. nov., isolated from hexachlorocyclohexane-contaminated soil, and emended description of Flavobacterium ceti Vela et al. 2007

A Gram-negative, strictly aerobic, yellow bacterial strain, designated DS-12(T), was isolated from hexachlorocyclohexane-contaminated soil in Lucknow, Uttar Pradesh, India. Strain DS-12(T) showed the highest 16S rRNA gene sequence similarity with Flavobacterium ceti 454-2(T) (94.2%). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain DS-12(T) belonged to the genus Flavobacterium. Strain DS-12(T) produced flexirubin-type pigments. Gliding motility was not observed. The major fatty acids of strain DS-12(T) were iso-C(15:0) (48.0%), summed feature 9 (comprising iso-C(17:1)ω9c and/or C(16:0) 10-methyl; 19.3%), iso-C(17:0) 3-OH (8.5%) and summed feature 3 (comprising one or more of C(16:1)ω7c, C(16:1)ω6c and iso-C(15:0) 2-OH; 7.2%). The only respiratory quinone was menaquinone-6 and the major polyamine was homospermidine. Strain DS-12(T) contained phosphatidyldimethylethanolamine, phosphatidylserine, phosphatidylethanolamine, one unknown phospholipid and one unknown aminolipid. The DNA G+C content was 37.4 mol%. Phylogenetic inference and phenotypic properties indicated that strain DS-12(T) represents a novel species of the genus Flavobacterium, for which the name Flavobacterium ummariense sp. nov. is proposed. The type strain is DS-12(T) (=CCM 7847(T) =MTCC 10766(T)). An emended description of Flavobacterium ceti is also given.

Endophytic and rhizoplane bacteria associated with Cytisus striatus growing on hexachlorocyclohexane-contaminated soil: isolation and characterisation

Inoculation of plants with their associated microorganisms is a promising strategy for improving phytoremediation of organic contaminants. Isolation and characterisation of these organisms from plants growing in contaminated sites will permit the identification of candidate strains for re-inoculation studies. The diversity of culturable endophytic and rhizoplane bacteria found in association with Cytisus striatus plants growing at a hexachlorocyclohexane (HCH)-contaminated site was studied. A total of 97 strains of endophytic bacteria were isolated from the root, stem and leaf tissues, and 49 from the rhizoplane. They were further characterised genotypically (BOX-PCR, 16S rDNA sequencing, presence of linA and linB genes) and phenotypically (trace metal tolerance, capacity to produce biosurfactants and plant growth promoting (PGP) traits). Proteobacteria and Actinobacteria dominated the isolate collection, and taxonomic diversity was strongly tissue-specific. The linA and linB genes were not detected in the isolate collection. The majority of isolates had at least one of the PGP traits tested, whereas biosurfactant-producing strains were less frequent. Resistance to more than one trace metal was generally restricted to endophytes isolated from shoot tissues. The PGP characteristics found in an important number of the bacterial isolates obtained in this study could be particularly useful for exploiting the phytoremediation potential of C. striatus.

Microbacterium lindanitolerans sp. nov., isolated from hexachlorocyclohexane-contaminated soil

A Gram-stain-positive, aerobic, rod-shaped, yellow actinobacterium, designated MNA2(T), was isolated from a hexachlorocyclohexane-contaminated soil in North India. Strain MNA2(T) showed 95 % 16S rRNA gene sequence similarity with Microbacterium halotolerans YIM 70130(T). Phylogenetic analysis of 16S rRNA gene sequences showed that strain MNA2(T) belonged to a clade represented by the genus Microbacterium of the family Microbacteriaceae. Strain MNA2(T) contained anteiso-C(15 : 0), anteiso-C(17 : 0), iso-C(16 : 0) and iso-C(15 : 0) as the predominant fatty acids and diphosphatidylglycerol, phosphatidylglycerol and two unknown polar lipids. The menaquinones were MK-12, MK-11, MK-13 and MK-10, in an approximate molar ratio of 45 : 40 : 13 : 3, respectively. The DNA G+C content was 65.3 mol%. The peptidoglycan was of the B type of cross-linkage with ornithine as the diagnostic diamino acid. The results of the phylogenetic, phenotypic and chemotaxonomic analysis indicate that strain MNA2(T) belongs to a previously unrecognized species of the genus Microbacterium, for which the name Microbacterium lindanitolerans sp. nov. is proposed. The type strain is MNA2(T) (=DSM 22422(T) =CCM 7585(T)).

Flavobacterium lindanitolerans sp. nov., isolated from hexachlorocyclohexane-contaminated soil

A Gram-negative, non-spore-forming, cream-yellow-pigmented bacterial strain, IP-10(T), was isolated from soil samples from a waste site highly contaminated with hexachlorocyclohexane in Ummari village, India. The organism showed the highest 16S rRNA gene sequence similarity of 92.7 % with Flavobacterium soli KCTC 12542(T) and levels of 87-92 % with the type strains of other recognized species of the genus Flavobacterium. The DNA G+C content of strain IP-10(T) was 31 mol%. The predominant fatty acids were iso-C(15 : 0) (22.1 %), iso-C(17 : 0) 3-OH (18.5 %) and summed feature 3 (comprising C(16 : 1)omega7c and/or iso-C(15 : 0) 2-OH; 13.2 %). Strain IP-10(T) could be differentiated from recognized species of the genus Flavobacterium based on a number of phenotypic features. Strain IP-10(T) is therefore considered to represent a novel species of the genus Flavobacterium, for which the name Flavobacterium lindanitolerans sp. nov. is proposed. The type strain is IP-10(T) (=MTCC 8597(T)=CCM 7424(T)).