The diversity of the actinomycete community associated with Neofibularia sp. from Bira Island, Indonesia, has been largely unstudied. This study was undertaken to address the paucity of information in this respect. Methodology and results: Culturable actinomycetes were isolated and cultured on HV medium. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) targeting the metagenomic 16S rRNA was used to analyse the structure of the actinomycete community. Five culturable actinomycetes that were isolated belonged to the genus Streptomyces. They showed various degrees of similarity to the reference strains Streptomyces sampsonii (97-99%), Streptomyces resistomycificus (97-99%), Streptomyces gougerotii (97-99%), Streptomyces erringtonii (97-99%), and Streptomyces albus (97-99%). The culturable actinomycetes isolates also showed differences in morphological characteristics as compared with the reference strains. The metagenomic analysis suggested that the actinomycete community was dominated by rare actinomycetes. Eight DGGE DNA bands that were obtained had sequences that showed similarities to Ferrithrix thermotolerans (88-94%), Lamia majanohamensis (87-92%), Aciditerrimonas ferrireducens (87-92%), and Thermobispora bispora (85-92%), while 4 bands had sequences similar to Propionibacterium acnes (97-100%) and another band matched sequences belonging to an uncultured bacterium clone (86-87%). The actinomycetes detected by the metagenomic approach were assigned identities that were mostly under 97.5% as compared with reference strains available in Genbank. Conclusion, significance and impact of study: Observations from both culture and DGGE analysis give a better understanding of the diversity and community structure of actinomycetes associated with Neofibularia sp. The culturable actinomycetes were Streptomyces spp., while rare actinomycetes were dominant when the metagenomic approach was adopted. Several of these actinomycetes showed identities below 97% when matched to reference strains, indicating possible novel species associated with the sponge Neofibularia.

Background: Kratom (Mitragyna speciosa Korth.) is widely used by the surrounding community as a traditional antidiabetic and antiobesity drug due to its high content of secondary metabolite compounds. The purpose of writing this review is to find out the bioinduction influence of Bacillus thuringiensis and Pseudomonas fluorescens and to find out the presence of an increase in secondary metabolites. Method: Writing and assessing source problems related to using literature study methods. Results: Kratom leaf methanol extract contains secondary metabolites of alkaloid groups, flavonoids, steroids/terpenoids, phenols and saponins. The main compound content of kratom leaves classified as alkaloids is mitragynine that has not been found in other plants. The administration of non-pathogenic bacteria such as Bacillus thuringiensis and Pseudomonas fluorescens can induce plant defenses and can accumulate the production of phenol compounds and flavonoids in plants. Conclusion: Based on the literature search results, kratom can indeed function as an antidiabetic and antiobesity and induction of microbes, namely Bacillus thuringiensis and Pseudomonas fluorescens bacteria can increase the content of secondary metabolites of plants. Through the increase in secondary metabolites, the efficacy of plants is higher to overcome health problems, namely antidiabetics and antiobesity.

Penelitian ini bertujuan mengetahui kemampuan 19 isolat cendawan endofit asal lada sebagai agens pengendali hayati. Sebagai variabel pengamatan penyakit berupa distribusi pada jaringan tanaman dan kemampuan daya hambat terhadap Septobasidium spp. Pengamatan juga dilakukan terhadap komponen agronomis berupa daya kecambah, panjang tunas, diameter pangkal tunas dan panjang akar. Perlakuan berupa pengujian 19 isolat cendawan endofit, unit perlakuan berisi 10 biji lada/pot yang disusun berdasarkan rancangan acak lengkap diulang sebanyak 3 kali. Hasil penelitian mendapatkan 6 isolat cendawan endofit yang memiliki daya hambat kuat terhadap Septobasidium spp dan tidak menimbulkan dampak merugikan bagi tanaman berupa Gliocladium sp. Aspergillus flavus, A. niger, Fusarium spp., Trichoderma spp. dan T. harzianum. Dua isolat agens hayati tersebut Gliocladium sp. dan T, harzianum bahkan mampu memacu pertumbuhan tanaman berkisar 27-29%.

Background: CPO refining which produces solid waste namely spent bleaching earth (SBE) in large quantities can pollute the environment. SBE from bentonite ores contains large amounts of silica, so it can be an alternative source of silica minerals. Silica plays an important role in increasing plant resistance and bioactive plant compound products. Methods: The application of Si in plants can increase secondary metabolites such as phenolic and anti-fungal compounds in response to disease pathogens. However, the low solubility of silica makes silica not sufficiently available for plants. Using microorganisms as silica solubilizing bacteria helps increasing solubility of silica in the soil. Bacteria dissolve silica by removing organic acids and producing indole acetic acid (AAI), which stimulates root hairs. Results: This review presents the results of a study on the utilization of silica-rich SBE waste as a source of available silica for plants with solubilizing method using bacteria to increase plant growth and resistance, as well as increase plant secondary metabolite compounds. Conclusions: The application of silica solubilizing bacteria has been known to play an important role in providing silica for plants, through enzymatic mechanisms, namely the production of organic acids and extracellular polysaccharides.

Protease is an enzyme that can hydrolyze proteins into simpler compounds such as small peptides and amino acids. The enzymes produced by microorganisms can be isolated by separating cells through centrifugation. The aims of the study was to determine the biological characteristics of the PrTK 02 bacterial isolate and the characteristics of the crude extract of the protease enzyme produced by the PrTK 02 bacterial isolate. The study was conducted by inoculated one ose PrTK 02 bacteria on the Nutrient Broth (NB) media. Pre-culture was carried out at 37 °C for 48 hours with an agitation speed of 120 rpm. Protease enzyme extraction was done by centrifugate the bacterial growth media at rate of 3000 rpm for 15 minutes at 4 °C. The Supernatant was tested for protease activity and protein content. The results of this study were obtained from the protease enzyme activity from bacterial isolate PrTK 02, marked by a clear zone in the Skim Milk Agar (SMA) medium. The highest enzyme activity were obtain with optimal production time by 24 hours with the specific activity by 1.2154 unit/mg protein. Biochemical and microscopic identification shows that the isolate of PrTk 02 bacteria is a class of Bacillus sp. PrTk 02 is a Gram-positive bacteria that is found in tempeh.