Isolationand Identification of Mixed Photosynthetic Microbial and Their Hydrogen Production
|School||Henan Agricultural University|
|Course||Agricultural Biological Environmental and Energy Engineering|
|Keywords||Mixed photosynthetic microbial Culture medium Separation and identification Hydrogen production|
This paper consists of a series research supported by the National Natural Science Foundation (No.50976029) and national "863" project (No. 2006AA05Z119).Research and development the technology of hydrogen production by photosynthetic bacteria, with crop stalks and livestock excrements as main raw material.Which is important to ensure the national energy security and achieve clean utilization the agricultural biomass resources. Isolation of high-efficiency bacteria as the main research fields of science and technology of hydrogen production by photosynthetic bacteria is obtained the widespread attention from energy and environmental science research workers. It is generally agreed that hydrogen production by pure cultured mycelium needs relatively strict sterile environment, higher cost and lower productivity. While photosynthetic bacteria has different absorption spectrum and property of using raw materials in the mixed microbial,there is Coordination effects among mixed microbial,so its has advantage is higher raw materials utilization and hydrogen production efficiency,Isolation of high-efficiency advantage mixed microbial is very important to drive the technology research progress of hydrogen production by photosynthetic organisms.This paper using special culture medium, hydrogen production mixed photosynthetic microbial was enriched from some sludge with plentiful light and organic compounds. Then isolation and identification the mixed photosynthetic microbial and optimum composition of hydrogen production culture medium for the mixed photosynthetic microbial was obtained through optimization research to increase the rate and amount of hydrogen production. Using optimum composition of hydrogen production culture medium, the hydrogen production characterization of mixed photosynthetic microbial was researched.The main content and result showed that:1. Using special culture medium, hydrogen production mixed photosynthetic microbial was enriched from five sites at Zhengzhou city. 2. Five strains non sulfur purple bacteria (hnau2-1, hnau2-3, hnau9-1, hnau11-5 and hnau12) were obtained according to separation and identification, hnau2-1 is Rhodospirillum rubrum of Rhodospirilum, hnau2-3 is R.capsulata and hnau11-5 is R.pulastris of Rhodopseudomonas, hnau9-1 is Rhodobacter capsulatus and hnau12 is Rhodobacter capsulatus of Rhodobacter.3. The various strains percentage among the mixed photosynthetic microbial is figured out according to strains with different colony morphology by plate colony-counting methods. Rhodospirillum rubrum is 27%, R.capsulata is 25%, R.pulastris is 28%, Rhodobacter capsulatus is 9% and Rhodobacter capsulatus is11%.4.The optimum composition of hydrogen production culture medium for the mixed photosynthetic microbial was obtained through optimization research, which is ammonium chloride 0.4g/L, magnesium chloride 0.2g/L, yeast extract 0.1g/L, potassium phosphate dibasic 0.5g/L,sodium chloride 2g/L, glucose concentration 56mM and sodium glutamate (MSG) 3.5 g/L, pH value7. Hydrogen-producing characters were studied as following:hydrogen production time of 204h longer than before ,the maximum hydrogen production amount of 3.41L/L,the maximal hydrogen production rate of 44.17ml/(L·h), the highest hydrogen content percentage of 46.73%.