Pyrosequencing analysis of bacterial diversity in soils contaminated long-term with PAHs and heavy metals: Implications to bioremediation.
Diversity, distribution and composition of bacterial community of soils contaminated long-term with both polycyclic aromatic hydrocarbons (PAHs) and heavy metals were explored for the first time following 454 pyrosequencing. Strikingly, the complete picture of the Gram positive (+ve) and Gram negative (-ve) bacterial profile obtained in our study illustrates novel postulates that include: (1) Metal-tolerant and PAH-degrading Gram -ves belonging to the class Alphaproteobacteria persist relatively more in the real contaminated sites compared to Gram +ves, (2) Gram +ves are not always resistant to heavy metal toxicity, (3) Stenotrophomonas followed by Burkholderia and Pseudomonas are the dominant genera of PAH degraders with high metabolic activity in long-term contaminated soils, (4) Actinobacteria is the predominant group among the Gram +ves in soils contaminated with high molecular weight PAHs that co-exist with toxic heavy metals like Pb, Cu and Zn, (5) Microbial communities are nutrient-driven in natural environments and (6) Catabolically potential Gram +/-ves with diverse applicability to remediate the real contaminated sites evolve eventually in the historically-polluted soils. Thus, the most promising indigenous Gram +/-ve strains from the long-term contaminated sites with increased catabolic potential, enzymatic activity and metal tolerance need to be harnessed for mixed contaminant cleanups.
Institute of Agriculture and Life Science, Gyeongsang National University, Jinju 52828, Republic of Korea; Centre for Environmental Risk Assessment and Remediation (CERAR), University of South Australia, Mawson Lakes, SA5095, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of Environment (CRC CARE), PO Box 486, Salisbury South, SA5106, Australia. Electronic address: saran.miles2go@gmail.com.
Saranya
S
Kuppusamy
Cooperative Research Centre for Contamination Assessment and Remediation of Environment (CRC CARE), PO Box 486, Salisbury South, SA5106, Australia; Global Centre for Environmental Remediation (GCER), Faculty of Science and Information Technology, The University of Newcastle, Callaghan, NSW 2308, Australia.
Palanisami
P
Thavamani
Centre for Environmental Risk Assessment and Remediation (CERAR), University of South Australia, Mawson Lakes, SA5095, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of Environment (CRC CARE), PO Box 486, Salisbury South, SA5106, Australia; Global Centre for Environmental Remediation (GCER), Faculty of Science and Information Technology, The University of Newcastle, Callaghan, NSW 2308, Australia.
Mallavarapu
M
Megharaj
Formerly Department of Microbiology, Sri Krishnadevaraya University, Anantapur 515055, India.
Kadiyala
K
Venkateswarlu
Institute of Agriculture and Life Science, Gyeongsang National University, Jinju 52828, Republic of Korea.
Yong Bok
YB
Lee
Centre for Environmental Risk Assessment and Remediation (CERAR), University of South Australia, Mawson Lakes, SA5095, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of Environment (CRC CARE), PO Box 486, Salisbury South, SA5106, Australia; Global Centre for Environmental Remediation (GCER), Faculty of Science and Information Technology, The University of Newcastle, Callaghan, NSW 2308, Australia.
Ravi
R
Naidu
D001315:Australia; D001673:Biodegradation, Environmental; D044822:Biodiversity; D006090:Gram-Negative Bacteria / Q000235:genetics / Q000302:isolation & purification*; D006094:Gram-Positive Bacteria / Q000235:genetics / Q000302:isolation & purification*; D019216:Metals, Heavy / Q000032:analysis*; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012988:Soil Microbiology / Q000592:standards*; D012989:Soil Pollutants / Q000032:analysis*
D019216:Metals, Heavy; D011084:Polycyclic Aromatic Hydrocarbons; D012336:RNA, Ribosomal, 16S; D012989:Soil Pollutants
Heavy metals; Microbial community; Mixed contamination; PAH degraders; Pyrosequencing