Transferring hydroponically grown Arabidopsis plants (Arabidopsis thaliana L.) to boron (B)-free medium kills the cells in root tips within an hour. To understand the mechanism underlying the induced rapid cell death, the Arabidopsis response to B deprivation was characterized using inhibitors of presumably involved cellular processes. The results suggest that stretching of the plasma membrane and the influx of calcium ions through mechanosensitive channels triggered the responses and that reactive oxygen species were overproduced under B-deprived condition. In addition, nitric oxide was observed to be involved in cell death, suggesting that Arabidopsis root cells undergo programmed cell death upon B deprivation. RNA sequencing analysis revealed that B deprivation induced transcriptome changes that resembled pathogen-induced responses. In summary, we speculate that B deprivation induces hypersensitive responses in Arabidopsis roots as a response to defective cell wall structures.

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Oil spill accidents occur several times in the Indonesian sea, including Jakarta Bay. Studies on the application of oil spill bio-degradation techniques need to be developed but require baseline data on microbe species diversity and functions. We isolated several bacteria from Pulau Pari that can degrade hydrocarbons (hexadecane, phenantrene, and dibenzothiophene) by using two step enrichment culture technique. The isolated microbes belong to several taxa, including α-subclass Proteobacteria, β-subclass Proteobacteria, γ-subclass Proteobacteria, the gram-positive high GC content (Actinobacteria), and Bacillus group. These marine bacteria degrade not only alkanes but also polyaromatic hydrocarbons (phenanthrene and dibenzothiophene). Alpha and gamma Proteobacteria were predominant alkane and polyaromatic hydrocarbons-degrading bacteria. The ability of those bacteria to degrade both alkanes and polyaromatic hydrocarbon is a key-important trait for enhancing bioremediation of oil spills.

Karst is a unique ecosystem that consists of a thin soil layer on the carbonate rocks. It has a diverse microorganism, especially actinomycetes group, which might potentially produce beneficial secondary metabolites that remain unknown. In this study, we were interested in isolating Dactylosporangium and Micromonospora that have been potentially reported as antibiotic sources. We used two methods using the chemical germicide (pretreatment 1.5% phenol) compared with the SDS-YE (0.05% SDS pretreatment). Thirty-nine isolates actinomycetes were successfully isolated from two samples of the karst cave soils. Thirteen isolates were obtained by using the germicide chemical method and closely related to the genera of Dactylosporangium and Micromonospora. On the other hand, the SDS-YE grew twenty-six isolates which closely related to 11 genera of actinomycetes (Catenulispora, Nocardia, Rhodococcus, Ornithinimicrobium, Catellatospora, Dactylosporangium, Micromonospora, Streptacidiphilus, Streptomyces, Nonomuraea, and Streptosporangium). These results suggest that 1.5% of phenol pretreatment could preserve the genera of Dactylosporangium and Micromonospora, while the Streptomyces and other rare actinomycetes were killed. Among all isolates, only 7 showed the antibacterial activity on tested bacteria. Even though the antibacterial activity of those isolates was not high, the isolation of actinomycetes from a specific substrate is necessary to be conducted on exploring the richness of our natural resources.

In fermented beverages, yeasts have been exploited for many years and are well-known as alcohol producers. In Indonesian traditional beverages, however, information about microbiology and potential bioactive-compounds of rice wine produced by the local people, especially in Lombok, are limited. The present study described the compounds of traditional rice wine including yeast species and its produced compounds that have biological activity. The yeast in rice wine was isolated using three growth agar media by serial dilution, selected the yeast colonies for molecular identification, and performed gas chromatography tandem with mass spectrometry for profiling the chemical compounds of the rice wine. The result indicated that the rice wine sold without distillation still contained Saccharomyces cerevisiae as the main alcohol producer. Meanwhile, at least six bioactive-compounds such as l-(+)-Ascorbic acid 2,6-dihexadecanoate, performic acid, octadecanoic acid, sulfurous acid, tetratriacontane, and eicosane were detected and reportedly related to antimicrobial, antiviral, anticancer, and other pharmacological activities. These findings could be the first step of studies on exploring Indonesian’s local rice wine as alcohol and bioactive-compound sources for health benefits.