In order to thoroughly investigate the diversity of glacier microorganisms, four DNA extraction methods with different lysis patterns were tested and two screened methods (the Bosshard-Bano method and the Zhou method) were optimized for the most effective form of the filter membrane (cut vs. uncut), the DNA extraction method, and the precipitation method. The two optimized methods were then compared with the commercial Mo-Bio DNA extraction kit, and the results showed that the kit was generally suitable for extraction of microorganism DNA from glacier surface snow. Procedurally, it was found that a modified Bosshard-Bano method (i.e., cutting the filter membrane into pieces, using a specific lysis pattern [lysozyme (5 mg/mL)-protease K (1 mg/mL)-CTAB (1%)-SDS (1%)], performing the extraction only once by chloroform-isoamyl alcohol (24:1), and conducting DNA precipitation by pure ethanol) was also an effective and less expensive method for extraction of microorganism DNA from glacier surface snow.
Four DNA extraction methods with different lysis patterns were used for extracting the DNA of glacier microorganisms (Gram-positive bacteria) cultivated in our laboratory,and the DNA yields of these four methods were estimated.The lysis patterns of the Bosshard-Bano and Zhou methods (i.e., lysozyme-protein K-CTAB-SDS) were better than those of the freezing-thawing and the Liu methods.Procedurally, cutting the filter membrane, extracting with chloroform only once, and precipitating with ethanol were shown to be more favorable for DNA extraction of glacier microorganisms. Comparison of these optimized traditional extraction methods with the Mo-Bio kit showed that, based on DNA parameters and PCR amplification, the kit method is suitable for study of microbial diversity in glacier surface snow, while the Bosshard-Bano method is also an effective and less expensive glacier microorganism DNA extraction method.
Introduction
