Sequential role of biosorption and biodegradation in rapid removal degradation and utilization of methyl parathion as a phosphate source by a new cyanobacterial isolate Scytonema sp. BHUS-5

ABSTRACT

A new isolate of genus Scytonema distinct from its closest relative cyanobacterium, Scytonema hofmanni was found efficient in the removal and degradation of organophosphorus (OP) pesticide, methyl parathion (MP). The cyanobacterial isolate was also capable of utilizing the phosphorus present in the MP following its degradation, which was evident from the increase in growth (chlorophyll content), biomass, protein content, and total phosphorus in comparison to cyanobacterium grown in phosphate-deficient cultures. The rapid removal of MP by the cyanobacterium during initial 6 hours of incubation was defined by the pseudo-second-order biosorption kinetics model, which indicated the involvement of chemosorption in initial removal of pesticide. Further, degradation of MP was also confirmed by the appearance of p-nitrophenol in the medium after 24 hours of incubation. Thus, the cyanobacterial isolate of Scytonema sp. BHUS-5 seems to be a potential bioremediation agent for the removal of OP pesticide, MP from the habitat.

KEYWORDS:

• organophosphorus
• Scytonema sp. BHUS-5
• methyl parathion
• biosorption
• biodegradation

Acknowledgments

The authors are thankful to the Head, Department of Botany, Banaras Hindu University, Varanasi, India, for providing necessary laboratory facilities and AIRF, JNU, New Delhi, for GCMS analysis.

Funding

Two of the authors (Balkrishna Tiwari and Ekta Verma) are thankful to the UGC for research fellowship (JRF and SRF). Sindhunath Chakraborty is thankful to ICAR-AMAAS for financial help in the form of SRF.