6 research outputs found
Soil Properties under Various Stages of Secondary Forests at Sarawak, East Malaysia
Change in the forest community during secondary succession is influencing in various soil properties. However, there is limited information available on the soil properties under different stages of secondary forests in Sarawak. The aims of this study are to clarify the soil morphological and physicochemical properties at secondary forests under different age stands after similar land change (slash and burn). Field surveys were conducted at 3, 5, 10, and 20 years old secondary forests in Sabal, Sarawak. Different fallow time influence changing soil properties in various stage secondary forests. A number of soil properties affected soil development process and land use change. Soil morphological and physicochemical properties differed and varied under different stages of fallow periods. The close relationship can be assumed between soil development process and vegetation succession. The knowledge of forest soil properties is essential to understand the change and development process under various stages secondary forests. The comprehensive understanding about soil properties and development process is important in order to conserve and manage secondary forests
Assessing genetic diversity among Brettanomyces yeasts by DNA fingerprinting and whole-genome sequencing
Brettanomyces yeasts, with the species Brettanomyces (Dekkera) bruxellensis being the most important one, are generally reported to be spoilage yeasts in the beer and wine industry due to the production of phenolic off flavors. However, B. bruxellensis is also known to be a beneficial contributor in certain fermentation processes, such as the production of certain specialty beers. Nevertheless, despite its economic importance, Brettanomyces yeasts remain poorly understood at the genetic and genomic levels. In this study, the genetic relationship between more than 50 Brettanomyces strains from all presently known species and from several sources was studied using a combination of DNA fingerprinting techniques. This revealed an intriguing correlation between the B. bruxellensis fingerprints and the respective isolation source. To further explore this relationship, we sequenced a (beneficial) beer isolate of B. bruxellensis (VIB X9085; ST05.12/22) and compared its genome sequence with the genome sequences of two wine spoilage strains (AWRI 1499 and CBS 2499). ST05.12/22 was found to be substantially different from both wine strains, especially at the level of single nucleotide polymorphisms (SNPs). In addition, there were major differences in the genome structures between the strains investigated, including the presence of large duplications and deletions. Gene content analysis revealed the presence of 20 genes which were present in both wine strains but absent in the beer strain, including many genes involved in carbon and nitrogen metabolism, and vice versa, no genes that were missing in both AWRI 1499 and CBS 2499 were found in ST05.12/22. Together, this study provides tools to discriminate Brettanomyces strains and provides a first glimpse at the genetic diversity and genome plasticity of B. bruxellensis