The microbial production of 1,3-propanediol (1,3-PD) by Klebsiella pneumoniae under micro-aerobic conditions was investigated in this study. The experimental results of batch fermentation showed that the final concentration and yield of 1,3-PD on glycerol under micro-aerobic conditions approached values achieved under anaerobic conditions. However, less ethanol was produced under microaerobic than anaerobic conditions at the end of fermentation. The batch micro-aerobic fermentation time was markedly shorter than that of anaerobic fermentation. This led to an increment of productivity of 1,3-PD. For instance, the concentration, molar yield, and productivity of 1,3-PD of batch microaerobic fermentation by K. pneumoniae DSM 2026 were 17.65g/l, 56.13%, and 2.94g l-1 h-1, respectively, with a fermentation time of 6 h and an initial glycerol concentration of 40g/l. Compared with DSM 2026, the microbial growth of K. pneumoniae AS 1.1736 was slow and the concentration of 1,3-PD was low under the same conditions. Furthermore, the microbial growth in fed-batch fermentation by K. pneumoniae DSM 2026 was faster under micro-aerobic than anaerobic conditions. The concentration, molar yield, and productivity of 1,3-PD in fed-batch fermentation under micro-aerobic conditions were 59.50g/l, 51.75%, and 1.57g l-1 h-1, respectively. The volumetric productivity of 1,3-PD under microaerobic conditions was almost twice that of anaerobic fedbatch fermentation, at 1.57 and 0.80g l-1 h-1, respectively.

A lactate oxidase was purified about 36-fold from a newly screened strain KY6 of gram negative bacterium from soil to yield a homogeneous protein. The native enzyme had a molecular mass of 204 kDa easured by Sephadex G-200 and that of subunit on the SDS-PAGE was found to be 45 kDa. The enzyme was optimally active at pH 7.7 and showed stability at pH range of 5.7 to 9.5 for 24 h at 4℃. The optimum temperature was 70℃ and the enzyme activity was stable for 10min up to 45℃. The half-life of the enzyme activity was about 10 min at 55℃. The best substrate of the enzyme was D-lactate and Km value for D-lactate was 0.14raM. The Km value for DL-lactate was 0.20mM. Substrate inhibition of the enzyme was observed at higher concentrations than 20mM of DL-lactate and 10mM of D-lactate.

Dibenzothiophene (DBT) is the most excessive and refractory sulfur compound in fossil fuels. The methods for removing DBT, using bacteria, were twofold: the first one involved the destruction of the carbon skeleton; the second, the use of a sulfur-specific process of biodesulfurization, without cleaving the carbon ring. Because the second method does not degrade the value of the fuel, it is considered by most researchers to be the method of choice. Bacteria used for this study, were obtained from the soil collected from a field that contained waste water from a refinery. Using GC/MS, it was confirmed that the metabolic pathway used by this bacterium, involved a sulfur-specific process of biodesulfurization, named the '4S pathway'. This strain appears to have the ability to remove the organic sulfur from thiophenic compounds over a wide temperature range from 25 to 45℃. And the half time of the whole cells desulfurization activity was 32 days, three times more than Rhodococcus erythropolis IGTS8. With the excellent stability, it may have industrial application for biodesulfurization.