Metagenomic Analysis of Airborne Bacterial Community and Diversity in Seoul, Korea, during December 2014, Asian Dust Event.

Asian dust or yellow sand events in East Asia are a major issue of environmental contamination and human health, causing increasing concern. A high amount of dust particles, especially called as particulate matter 10 (PM10), is transported by the wind from the arid and semi-arid tracks to the Korean peninsula, bringing a bacterial population that alters the terrestrial and atmospheric microbial communities. In this study, we aimed to explore the bacterial populations of Asian dust samples collected during November-December 2014. The dust samples were collected using the impinger method, and the hypervariable regions of the 16S rRNA gene were amplified using PCR followed by pyrosequencing. Analysis of the sequencing data were performed using Mothur software. The data showed that the number of operational taxonomic units and diversity index during Asian dust events were higher than those during non-Asian dust events. At the phylum level, the proportions of Proteobacteria, Actinobacteria, and Firmicutes were different between Asian dust and non-Asian dust samples. At the genus level, the proportions of the genus Bacillus (6.9%), Arthrobacter (3.6%), Blastocatella (2%), Planomicrobium (1.4%) were increased during Asian dust compared to those in non-Asian dust samples. This study showed that the significant relationship between bacterial populations of Asian dust samples and non-Asian dust samples in Korea, which could significantly affect the microbial population in the environment.

Comprehensive metabolic profiles of mulberry fruit (Morus alba Linnaeus) according to maturation stage.

In this study, comprehensive metabolic profiles of mulberry fruits (Morus alba Linnaeus) at various maturation stages were determined using GC-MS and HPLC. In total, 48 compounds, including 3 alcohols, 16 amino acids, 7 organic acids, 2 sugars, 4 phenolics, 2 terpenes, 3 vitamins, 9 fatty acids, and 2 cyanidins were identified in the mulberry samples. Levels of chlorogenic acid, cryptochlorogenic acid, neochlorogenic acid, ascorbic acid, and δ-tocopherol, and total fatty acid content were significantly higher in the semi-matured mulberry fruits. Furthermore, levels of glycerol, citrate, fructose, glucose, 3-O-glucoside, and cyanidin-3-O-rutinoside were significantly higher at the fully matured stage than at the other stages. Twelve biosynthetic pathways were suggested as major pathways involved in mulberry fruit maturation. The information obtained in this study will provide a basis for future investigations toward quality control or metabolic engineering for development of mulberry fruits possessing commercially valuable characteristics.