Wulan R, Astuti RI, Rukayadi Y, Meryandini A. 2021. Evaluation of Indigenous Pichia kudriavzevii from cocoa fermentation for a probiotic candidate. Biodiversitas 22: 1317-1325. Currently, probiotics are becoming a concern along with a healthy lifestyle awareness. Besides bacteria, yeast can be used as a probiotic candidate with specific functional properties. Research on yeast as a probiotic is still limited (except for Saccharomyces boulardii). Previous research has isolated yeasts from the cocoa fermentation process. This study aimed to evaluate the probiotics properties and antioxidant activity of yeast strains isolated from spontaneous cocoa fermentation in Sukabumi, Indonesia. Previous research has isolated 23 yeast strains from spontaneous cocoa (Theobroma cacao L.) fermentation. Of the 23 yeast strains isolated from cocoa fermentation, 22 strains showed negative hemolysis as an indicator of non-pathogenic properties. Ten yeast strains were able to grow at 37 °C and 41 °C, pH 3, 0.5% bile salts, had autoaggregation ability (63.99-95.33%), and co-aggregation with S. typhimurium ATCC14028 (>80%), as character requirement for probiotic candidates. The genetic identification of the ten yeast strains showed that they were 99% identical to Pichia kudriavzevii. Based on its antioxidant activity, the P. kudriavzevii 2P10 metabolites had the highest percentage of inhibition (68.51%) against DPPH free radicals and resistance to H2O2 oxidative stress up to 3 mM. It can be concluded that P. kudriavzevii 2P10 is a promising probiotic candidate for functional foods and health purposes.

This research aims to select the potential lactic acid bacteria (LAB) for starter culture for cocoa beans fermentation. The bio-control activity against mycotoxigenic fungi were also evaluated. The indigenous LAB was analized from Sukabumi cocoa beans fermentation by spontaneous method for four days (96 hours). The preliminary screening of LAB were observed by clear zone forming, morphology characterization and catalase activity. The LAB were screened for their ability to resist acidity, ethanol, and heat, and their ability to produce high acid and antifungal. The antifungal capability was antagonistic assays to Aspergillus ochraceus IPBCC 88.033 on Potato Dextrose Agar (PDA) medium. The result showed that the selected acid bacteria isolate, H 2.34, were antifungal-producing strains, and resist acidity, ethanol and heat, which was suitable property for starter culture and biopreservation agent. The study demonstrated the selection of local Indonesian LAB from Sukabumi fermented cocoa bean to observe the potential of isolate as a starter culture and biopreservation agent

Agustina S, Wiryawan KG, Suharti S, Meryandini A. 2021. The enrichment process and morphological identification of anaerobic fungi isolated from buffalo rumen. Biodiversitas 23: 469-477. Anaerobic fungi are one of the microbes that have an important role in rumen fiber degradation because they can produce cellulase enzymes and penetrate feed particles. Nevertheless, few studies were performed to test the potential of anaerobic fungi in Indonesia. Therefore, the present study was carried out to evaluate the impact of the enrichment process on pH value, the zoospores population, NH3 (ammonia) concentration, and VFA (Volatile Fatty Acid) proportion. In addition, this research was also performed to isolate anaerobic fungi from buffalo rumen and identify their morphological characteristics. The enrichment stage of anaerobic fungi was carried out using the Hungate method. Results showed that the population of fungi zoospores, pH value, ammonia concentration, the proportion of acetate, and total VFA were significantly affected by the incubation time (P<0.01). In addition, Caecomyces, Neocallimastix, and Piromyces were rumen anaerobic fungi isolated from buffalo rumen with different morphological characteristics. It can be concluded that the incubation time increased the zoospore population, the concentration of NH3, acetate proportion, and total VFA but decreased media's pH value.

The fermentation of the coffee fruit processing into coffee beans leaves the fermented coffee pulp which still contains polyphenol secondary metabolites. This study aimed to analyze the total flavonoid content (TFC) and total phenolic content (TPC) of fermented robusta coffee pulp (Coffea canephora L.) by using indigenous Actinomycetes. The ability of fermented extracts to inhibit free radical DPPH (2,2-diphenyl-1-picrylhydrazyl) also were done. In this study, coffee cherries were fermented in the solid-state fermentation cultivation (SSF) using isolates HJ4.5b, P2b(b).3 and P2b(b).18 which in previous studies were reported to have cellulolytic and xylanolytic activities. Determination of molecular identification base on 16S rRNA gen showed the isolates HJ4.5b and P2b(b).3 have similarities to the genus Streptomycetes, while P2b(b).18 has a homologous base arrangement with a rare actinomycetes genus Micromonospora. Fermentation using P2b(b).3 on the 9th day of fermentation indicated the highest percentage increase in TFC (295.54%) with IC₅₀ 18.41 µl/ml and having an antioxidant activity index (AAI) value of 2.14 which was included in the very strong antioxidant activity category.

Recombinant insulin is a vital medicine for diabetic patients. This hormone is produced by microbes such as Pichia pastoris that carry the recombinant gene of a human insulin precursor (HIP). Large-scale protein production involves a bioreactor to promote the optimal condition for the yeast to express the protein target. In order to obtain a large amount of insulin, the cultivation of recombinant P.pastoris/pD902-IP carrying human insulin precursor gene in a bioreactor 10 Liter was developed. The isolate was cultivated in a half concentration of basal salt media for 124.5 hours. Induction of the protein was done by continual methanol feeding. The fermentation condition was set to have a temperature at 28°C, agitation at 300 rpm, aeration at 2 L/min and a pH value of around 5. Dry cell weight (DCW) was measured, and HPLC quantified the content of HIP, glycerol and methanol. This work’s DCW and HIP concentrations were 46.5 g/L and 928 mg/L, respectively. The results can be higher by increasing the number of cells in the culture or extending the cultivation time so that the HIP concentration may exceed 1 g/L.