Search

Diverse microorganisms from the three domains of life (Archaea, Bacteria, and Eukaryota) cause deterioration in mural paintings worldwide; however, few studies have simultaneously targeted these three domains. This study aims to survey the microbiome and its potential for biodeterioration on unpreserved Lan Na mural paintings in Sean Khan temple, Chiang Mai, Thailand. The overview of the archaeal, bacterial, and fungal communities was reported by Illumina sequencing, whereas the potential for deterioration was revealed by culturable techniques and a literature search. The abundant microbes reported in this study were also found in other ancient mural paintings worldwide. Halococcus, a salt-tolerant archaeon, as well as the eubacterial genus Crossiella dominated the prokaryotic community. On the other hand, the main fungal group was the genus Candida (Ascomycota). However, a low number of fungi and bacteria were isolated. Most of the isolates showed the ability to survive in the drought conditions of mural paintings but could not perform discoloration activities. The deterioration activity mainly affected calcium compounds, which are the main components of painting substrates. Aspergillus and several bacterial isolates could dissolve calcium compounds, but only Trichaptum species could induce crystal formation. These results suggest that deterioration of painting substrate should be taken into consideration in addition to deterioration of color in mural paintings. For the Lan Na painting in Sean Khan temple, the plaster is the prime target for biodeterioration, and thus we suggest that the preservation effort should focus on this component of the mural painting. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the lactic acid bacteria in stingless bees (Lepidotrigona terminata). Stingless bees were randomly collected from five different nests in Chiang Mai University, identified via the COI gene, and compared to those in the NCBI database. The result showed that all samples were L. terminata. Bees were extracted and subjected to 10-fold dilution to screen on MRS agar to estimate the number of lactic acid bacteria (LAB) cells in the samples. The colony forming unit (CFU) was between 1.28 x 10 6 ± 0.02 and 1.37 x 10 6 ± 0.08 CFU/g. Fifty isolates were chosen to perform an agar well assay to quantify the capacity of inhibiting against Paenibacillus larvae (strain LMG9820), a honey bee pathogen that causes American foulbrood. The results showed that bacteria from two nests (selected from those of the five nests) could inhibit the growth of P. larvae with the mean of a clear zone of 12.15 ± 0.2 mm. On the other hand, bacteria from the other three nests could not inhibit the pathogen. Identification of the effective bacteria species using 16S rRNA and the construction of the phylogenetic tree revealed that they were Fructobacillus fructosus of the Bacillus group. The cultured-independent result showed that Betaproteobacteria was the most abundant group (41.6%) of bacteria in stingless bees while Actinobacteria was the lowest in abundance (0.6%). Further experiments will need to be performed to examine the functions of these microorganisms in stingless bees. [ABSTRACT FROM AUTHOR]