Asian-Pacific Aquaculture 2019

June 19 - 21, 2019

Chennai Tamil Nadu - India

ISOLATION AND CHARACTERIZATION OF SALT PAN BACTERIA FOR DEVELOPING BACTERIAL CONSORTIUM FOR THE COMPLETE REMOVAL OF NITROGEN FROM AQUACULTURE POND

Jojy johna, Amit kumara, Vinu S Sivab, Balasubramanian Vb and Sasi kumar Gb
 
a Centre for Climate Change Studies, Sathyabama Institute of Science and Technology, Jeppiaar Nagar, Rajiv Gandhi  Road, 
Chennai - 600 119.
b Amazing Biotech Pvt Ltd, No.424/3, Easwaran Koil South, ECR Main Road, Near Aircel Tower, Marakkanam, Villupuram Dt. - 604 303.
 

Aquaculture has become a major economic activity around the world in food production sector, and the annual production has been raised up to 300 million metric ton (FAO, 2016). In India, the total shrimp production has been reached around 4, 97, 622 metric ton in the year 2015 -16. Over the last five years, the culture area has been considerably increased from high saline to low saline area. Due to heavy intensification of aquaculture activity, managing nitrate pollution in aquaculture ponds during culture period has become a challenge. Using microbes to remove nitrogenous waste is a better way for the waste management. Denitrification process is an important reductive process (NO3 into N2) to manage nitrate pollution. The intermediates such as nitrite and ammonia are toxic to both fresh water and marine aquatic animals. For the complete nitrogen waste removal, aerobic denitrificans are recently interested, which can use both oxygen and nitrate nitrogen as the terminal electron acceptors. Hence, developing consortium of bacterial population for the management of multiple nitrogen contaminants and to remove complete nitrate without nitrite accumulation from water and solid nitrogeneous waste are essential for aquaculture waste management. Halophilic bacteria can resist most of the rigid conditions, and also overcome high saline complications in most of the aquatic pond. Hence, in the present study, we identify bacteria capable for nitrogen removal from saltpan and develop a consortium for simultaneous nitrification and denitrification without nitrite accumulation. The sediment and water sample from Marakkanam saltpan was collected and bacteria were isolated either through direct plating or enrichment techniques. The isolated bacterial cultures were identified as Halovibrio denitrificans by polyphasic taxonomy including biochemical assays, and 16S rRNA gene sequencing. The nitrogen removal capacity was measured by spectrophotometric method, and role of enzymes in the reduction of nitrogen were tested using qRT-PCR technique. From the data, we found that the nitrate was reduced to nitrite within 6 hours but nitrite was not further reduced completely under aerobic condition. However, the accumulation of nitrate and nitrite were completely reduced under anaerobic condition within 3 hours of treatment. Hence, these kind of environmental bacterial consortium will be helpful for waste treatment system in aquaculture and other industrial waste management, in which, H. denitrificans will a play vital role.