The Screening Of Microbial Strain For Biological Purification Of Maltose

Maltose is two glucose units obtained by the ?-amylase hydrolysis the non-reducing ends of starch. Maltose has been widely used in food industry, as it was characterized by low moisture absorption, moisture resistance, low sweetness, not prone to color and preventing dental caries. Metabolism of maltose is slow and doesn't need insulin, so it also has been widely used in pharmaceutical industry. With the widening application areas of maltose, such as maltose purity need to reach 99%or more in maltose injection, maltose is increasing the requirements of purity. Products of starch hydrolysis are maltose, glucose, maltotriose, maltotetraose and maltooligosaccharige. At the current level of production technology, the most pure maltose concentrations can reach 90%-95%,when only use the enzymes to hydrolyze starch. It is difficult to significantly improve the purity, even with separation techniques such as ion exchange chromatography. Furthermore, these separation methods are not easy and the production cost will become higher. In this paper, the main purpose is to select and separate one strain, which can hydrolyze maltotriose, maltotetraose and maltooligosaccharige, then study the characteristical of crude enzyme.One strain has been selected and separated from soil,which can hydrolyze maltotriose, maltotetraose and maltooligosaccharige. This strain was named MGL-1. According to the research of physiological and biochemical characteristics and phylogenetic analysis based on 16S rDNA sequences, The strain was identified as Burkholderia and this strain is aerobic bacteria, Gram-positive and endospore-forming short bacillus. The localization of degrading enzyme from MGL-1 was tested. It was observed that the cell wall enzymes and extracellular enzymes could hydrolysis the maltotriose, maltotetraose and maltooligosaccharige, but the intracellular enzyme couldn't. In addition, intracellular enzyme could increase the content of maltose. The results showed that the active substances were cell wall enzymes. TLC analysis showed that the optimum temperature for crude enzyme was 45?. The optimum pH for crude enzyme was 5.0.