Abstract. Setyati WA, Pringgenies D, Soenardjo N, Pramesti R. 2023. Enzyme-producing symbiotic bacteria in gastropods and bivalves molluscs: candidates for bioindustry materials. Biodiversitas 24: 20-25. Biotechnology plays a vital role in modern civilization because almost all aspects of human life have benefited from the development of biotechnological applications, especially in the bioindustry. Therefore, the present study aims to obtain bacterial isolates from molluscs and identify those with the potential to produce protease, amylase, and cellulase enzymes using bimolecular methods and bacterial biochemical analysis. The samples were collected in April 2022 from the coastal waters of Krakal, Special Region of Yogyakarta, Indonesia. The symbiotic bacteria were isolated, and screened for different enzymatic activity. The molecular method (16S rRNA gene sequence) was used to identify acterial isolates with the highest potential for enzymatic activity. Biochemical analysis of isolates that are potential candidates for industrial materials was carried out using the thin-Layer Chromatography (TLC) method to detect the compounds produced by bacteria. The results showed that the bacterial isolates GS 1-4, GS 2-1, and GS 2-12 had similarity with Alcaligenes faecalis (99.83%), Alcaligenes faecalis (99.74%) and Alcaligenes aquatilis (98.51%) respectively. The three isolates showed the potent enzymatic activity and contained alcohol, amines, aldehyde, ketone and conjugated aromatics, as well as amino acids for potential candidates of bioindustry materials.

Abstract. Sibero MT, Frederick EH, Sabdono A, Wijayanti DP, Pringgenies D, Radjasa OK, Zilda DS, Murwani R. 2022. First report of seaweed-associated yeast from Indonesia: Species composition and screening of their polysaccharides-degrading enzymes. Biodiversitas 23: 1408-1419. Yeast has been widely utilized in various industries due to its enzyme properties. Therefore, plenty of studies focus on exploring yeast biodiversity from diverse sources. However, there are limited reports regarding marine yeast biodiversity and its potential from Indonesia. This study aimed to isolate and identify the seaweed-associated yeast from Jepara in Central Java and Sepanjang Beach in Gunung Kidul, Yogyakarta, then examined their potential to produce extracellular polysaccharides-degrading enzymes (EPEs). Marine yeasts were isolated using standard marine agar (STD) and potato dextrose agar (PDA). All isolates were characterized by their salinity tolerance, morphology, and species confirmation using DNA barcoding. Three EPEs consisting of agarase, alginate-lyase, and carrageenase were screened using polysaccharides-enriched agar media. A specific agarase encoding gene was detected with specific primers. In total, 21 seaweed-associated yeast were successfully isolated from 6 seaweeds and noted as facultative marine yeast. The DNA barcoding study discovered that these yeasts belonged to 5 genera, consisted of Aureobasidium, Candida, Debaryomyces, Hortaea, and Rhodotorula. Moreover, Candida was noted as the most abundant genus (71.42%). It was noted that Hortaea werneckii MTJ.11 and MTJ.13 were positive for all enzymes; Aureobasidium melanogenum MTGK.31 gave a positive result for agarase and carrageenase; while [Candida] zeylanoides MTGK.23 only exhibited alginate-lyase activity. Unfortunately, none of the primers used to detect the presence of genes encoding polysaccharide-degrading enzymes were successfully amplified.

Abstract. Fatmawati F, Sibero T, Trianto A, Wiyanti DP, Sabdono A, Pronggenies D, Radjasa OK. 2022. The influence of fermentation using marine yeast Hortaea werneckii SUCCY001 on antibacterial and antioxidant activity of Gracilaria verrucosa. Biodiversitas 23: 5258-5266. Gracilaria verrrucosa is producer of agar, a polysaccharide, that widely used in pharmaceutical and food industries. However, several studies have shown that the secondary metabolite of this seaweed is not potential as an antimicrobial and antioxidant agents. This study aimed to determine the antibacterial and antioxidant properties of methanolic extract of G. verrucosa after fermentation using marine yeast Hortaea werneckii SUCCY001. The samples were fermented based on different optimization times, specially in three, six and nine days. Samples were extracted using methanol by maceration method. Then the extracts were tested for antimicrobial potential against the several human clinical pathogens namely Bacillus cereus, Bacillus subtilis, Escherichia coli, Micrococcus luteus and Pseudomonas aeruginosa. The antioxidant potential was analyzed using the 1,1-diphenyl-2-picrylhydracyl (DPPH) and 2,2-Azinobis 3-ethyl benzothiazoline 6- sulfonic acid (ABTS) method while total phenolic content (TPC) was measured using Folin-Ciocalteu. Secondary metabolites were characterized using thin layer chromatography (TLC) and GC-MS. TLC plate visualization using UV light, DPPH, FeCl3 and vanillin-sulfuric acid  reagents. The results showed that the extract fermented for nine days was able to inhibit the growth of P. aeruginosa and M. luteus at a concentration of 2 mg/mL. The highest antioxidant activity was found in the nine days fermented extract with an RSA value of 21.9% ± 0,0001 for DPPH and 12.53 % ± 0.002 for ABTS. Furthermore, the highest total phenolic content was found in the nine days fermented extract of 7.57 GAE/mg. The results of characterization using TLC showed the presence of phenolic compounds, terpenoids and antioxidants in fresh seaweed extracts, autoclaved fresh seaweed, three days of fermentation, six days and nine days. Based on this research, it can be seen that the addition of marine yeast starter H. werneckii SUCCY001 was able to increase the antibacterial and antioxidant activity of G. verrucosa.

Abstract. Fatmawati F, Sibero T, Trianto A, Wiyanti DP, Sabdono A, Pronggenies D, Radjasa OK. 2022. The influence of fermentation using marine yeast Hortaea werneckii SUCCY001 on antibacterial and antioxidant activity of Gracilaria verrucosa. Biodiversitas 23: 5258-5266. Gracilaria verrrucosa is producer of agar, a polysaccharide, that widely used in pharmaceutical and food industries. However, several studies have shown that the secondary metabolite of this seaweed is not potential as an antimicrobial and antioxidant agents. This study aimed to determine the antibacterial and antioxidant properties of methanolic extract of G. verrucosa after fermentation using marine yeast Hortaea werneckii SUCCY001. The samples were fermented based on different optimization times, specially in three, six and nine days. Samples were extracted using methanol by maceration method. Then the extracts were tested for antimicrobial potential against the several human clinical pathogens namely Bacillus cereus, Bacillus subtilis, Escherichia coli, Micrococcus luteus and Pseudomonas aeruginosa. The antioxidant potential was analyzed using the 1,1-diphenyl-2-picrylhydracyl (DPPH) and 2,2-Azinobis 3-ethyl benzothiazoline 6- sulfonic acid (ABTS) method while total phenolic content (TPC) was measured using Folin-Ciocalteu. Secondary metabolites were characterized using thin layer chromatography (TLC) and GC-MS. TLC plate visualization using UV light, DPPH, FeCl3 and vanillin-sulfuric acid  reagents. The results showed that the extract fermented for nine days was able to inhibit the growth of P. aeruginosa and M. luteus at a concentration of 2 mg/mL. The highest antioxidant activity was found in the nine days fermented extract with an RSA value of 21.9% ± 0,0001 for DPPH and 12.53 % ± 0.002 for ABTS. Furthermore, the highest total phenolic content was found in the nine days fermented extract of 7.57 GAE/mg. The results of characterization using TLC showed the presence of phenolic compounds, terpenoids and antioxidants in fresh seaweed extracts, autoclaved fresh seaweed, three days of fermentation, six days and nine days. Based on this research, it can be seen that the addition of marine yeast starter H. werneckii SUCCY001 was able to increase the antibacterial and antioxidant activity of G. verrucosa.