Asia Life Sciences

Abstract : Honeybees are vulnerable to many diseases, such as European foulbrood, chalkbrood, sacbrood, and American foulbrood (AFB). Caused by Paenibacillus larvae, AFB can cause immense damage to the bee industry. Chemicals and antibiotics have long been used to treat these diseases, resulting in pathogen resistance. As an alternative, antagonistic effect of gut bacteria has been focused on. The culture supernatant (CS) from recently isolated gut bacteria from Thai Apis cerena indica (Bacillus sp., Pantoea sp., Azotobacter sp., Klebsiella sp., and Lactobacillus sp.) were screened for their growth inhibitory activity against P. larvae strains 01 and 02 in an agar well diffusion assay. The CS from Azotobacter sp. had the highest growth inhibition against P. larvae strain 02, while the CS from Bacillus sp., Lactobacillus sp., Klebsiella sp., Azotobacter sp. were all active against both strains. This activity was thermotolerant to 90 ºC for 1 h, but 121 ºC nor to proteinase K and RNase A treatment. Furthermore, the CSs from Bacillus sp. and Klebsiella sp. at pH 3, Pantoea sp. at pH 5, Lactobacillus sp. at pH 8 and 10, and Klebsiella sp. at pH 10 showed the highest inhibitory effect against P. larvae strains 01 and 02. However, the CS inhibitory activity at pH 8–10 was less than that at pH 5 (the pH in the bee stomach). Hence, gut bacteria that can potentially inhibit P. larvae growth were obtained from healthy honeybees.

Abstract : Apis dorsata are important pollinators, while their honey is the most popular for consumption in Asia. Although they have an aggressive and very thorough grooming behavior, ectoparasitic mites that can act as disease vectors have been reported. Here, the presence of mites on different developmental stages of A. dorsata was investigated in three hives in Samutsongkram province in February, 2021 to reveal the health status of A. dorsata in Thailand. No ectoparasitic mites were observed under stereo and compound light microscopy based examination of 150 adult bees (50 bees/hive). In contrast, phoretic mites were found on the bee’s thorax, principally the legs of pair no. 3. Morphological analyses, including scanning electron microscopy, placed the mites in the order Oribatida, and possibly Forcellinia faini, but this awaits molecular confirmation. Prevalence of adult bees with phoretic mites from hive no. 1, 2, and 3 was 32%, 20%, and 30%, respectively, with a range of 0–10 mites per bee. No mites were observed on non-adult stadia. No Paenibacillus larvae, which causes American foulbrood disease, was detected in the mites by multiplex PCR using specific primers for 16S rRNA of bacteria and cytochrome b (cytb) for Apis spp. under an optimized PCR condition. Rather the bacterial amplicon showed a 91.5% nucleotide sequence identity to Lactobacillus fermentum (probiotic bacteria). The ecologic impact of this relationship between phoretic mites, probiotic bacteria, and honeybees, as well as the effect of mites on pollination by A. dorsata, needs to be determined.

Abstract :

A total of 180 trawler and 180 gillnet fishing households were interviewed for fishing activities while fish traders/retailers (30) were interviewed for determination of fish channel market. Economic fish species composition was determined through sampling of 30 trawlers and 30 gillnets households. The results showed that trawl and gillnet fishing operated year-round. Fishing voyage of trawl was shorter, 1.9 days in average while fishing voyage of the gillnet has been unchanged. Fishing yield calculated per HP of trawlers (0.895 ton/HP/year) was seven time higher than that of gillnets (0.128 ton/HP/year). The rate of trash fish in trawler and gillnet in this study reduced. The economic efficiency of trawlers and gillnet have been improved. A large proportion of total fishery products was sold to traders/wholesalers and then transported to the processing factories and sold to the retailers in the local markets. Economic fish species from the two fishing activities has shown the typical species catching following types of fishing gears. Inclement weather and lack of capital are two main constrains for the fishing careers

Abstract :

A two-factorial experimental design was used to evaluate the combined effect of three stocking densities—500, 750, and 1,000 ind./L—and three C/N ratios—5, 10, and 15—on the growth and biomass production of Artemia franciscana. Artemia nauplii (newly hatched) were reared in 1.5 L bottles containing 1 L of sea water at 30‰. Molasses with a 38% carbon content was used as carbon source to stimulate bacterial growth in the Artemia culture medium. Results showed that the manipulation of C/N at 5 and 10 promoted better growth of Artemia in terms of length compared to that obtained by Artemia in the higher C/N ratio. However, it was not clear whether there was an increase of growth performance in the culture where Artemia were reared at high densities. Moreover, the addition of molasses produced a biomass in stocking density at 500 ind./L that was nearly similar to that obtained in the 750 and 1,000 ind./L

Abstract :

Containing high-quality RNA is the basis of plant molecular biology research, plant genetics and other physiological investigations. At present, several plant RNA isolation methods have been utilized to received high-quality RNA yield. However, there are not much research data regarding RNA resistance after RNA isolation stage. This study attempts to elaborate on the effects of RNA storage on RNA quality for general molecular biology experiments such as Reverse Transcriptase PCR to obtain specific DNA fragments. Temperature and concentration were chosen because they are the most basic factors that can affect RNA quality. The samples were checked using Nanodrop spectrophotometer and gel electrophoresis for testing purity, quantity and integrity of RNA. Based on this experiment, total RNA from sugarcane can be stored at -40 °C and -20 °C for a month without significant quality quantity reduction. Both storage temperatures allow the quality of RNA to be maintained at a sufficient level for use in cDNA synthesis and gene-specific amplification without additional treatment. Storing pure RNA at a sufficiently high concentration would be more advantageous for the next experimental stage