Project Number: 5368-13000-007-05
Project Type: Nonfunded Cooperative Agreement

Start Date: Jan 01, 2009
End Date: Dec 31, 2010

Objective:
This non-funded cooperative agreement will focus on the characterization of salt tolerant microorganisms in California¿s Death Valley salt pan. Traditional microbiological and molecular techniques will be utilized to isolate and identify the microorganisms, respectively. A major thrust of the research will be geared towards characterizing salt tolerance genes and identifying isolates for biotechnological applications. Specific project objectives will be: 1. Utilize traditional and molecular techniques to isolate and identify salt tolerant microorganisms in the Death Valley salt pan. 2. Characterize genes that express salt tolerance and allow microorganisms to survive in extreme environments. 3. Screen salt tolerant isolates that may be useful for biotechnological applications. 4. Complete a chemical characterization of the salt pan samples.

Approach:
To isolate bacteria from the salt pan samples using culture-dependent techniques, a dilution series of the samples will be directly plated on the following media: Marine agar, 10% Tryptic Soy agar, R2A, Potato Dextrose agar, and Rose Bengal agar. For the culture-independent approach, DNA will be extracted from the salt pan samples, PCR-amplified and cloned, and identified by sequence analysis of the 16S rRNA genes. Documents NFCA with Gyeongbuk Institute for Marine Bio-Industry. Studies on hyperosmotic adaptation and salt tolerance in Death Valley bacterial isolates will be performed to examine cellular responses to environmental salinity. In particular, we will characterize the bacteriorhodopsin gene, sodium pump gene, osmo-responsive gene, and biopolymer gene. To determine the potential of salt tolerant isolates in biotechnological applications, they will be screened for a variety of biopolymers and enzymes. Biopolymers, such as biosurfactants and exopolysaccharides, are of interest for microbially enhanced oil recovery. Other useful biosubstances are enzymes, such as new isomerases and hydrolases that are active and stable at high salt contents. Halotolerant microorganisms play an essential role in food biotechnology for the production of fermented foods and food supplements. In addition to the microbial characterization, the salt pan samples will be analyzed for a variety of trace metals using inductively coupled plasma-atomic emission spectrometry and atomic absorption spectrometry after microwave acid digestion. The pH, electrical conductivity, carbon content, and nitrogen and phosphorus concentrations will also be determined in the samples.