Antifungal strains and gene mapping of secondary metabolites in mangrove sediments from Semarang city and Karimunjawa islands, Indonesia

Abstract

<abstract> <p>Infection caused by pathogenic fungal species is one of the most challenging disease to be tackled today. The antifungal bacteria candidate can be found in terrestrial as well as aquatic ecosystems, with mangrove forests being one of them. The purpose of this study is to obtain candidate isolates of antifungal strains with a detection approach and gene mapping simulation of bioactive compounds producers and screening to determine qualitative antifungal activity. The research will be carried out by collecting sediment samples from the mangrove ecosystems of Karimunjawa and Mangkang sub-district of Semarang city, isolating and purifying bacteria with Humic Acid Vitamin Agar (HVA), International Streptomyces Project 1 (ISP 1) and Zobell (Marine Agar). added with antibiotics, qualitative antifungal ability screening of each isolate obtained, detection of the presence of PKS gene and NRPS using special primers using the Polymerase Chain Reaction (PCR) method, and molecular identification of each isolate by 16s rRNA sequencing method. Of the total 59 isolates produced from the sample isolation process, 31 isolates from Karimunjawa sediments and 8 isolates from Semarang sediments showed activity against test pathogenic bacteria, namely <italic>Candida albicans</italic>, <italic>Trichoderma</italic> sp., and <italic>Aspergillus niger</italic>. Detection of Biosynthethic Gene Cluster (BGC) showed that the genes encoding secondary metabolites (NRPS, PKS 1 and PKS 2) were detected in KI 2-2 isolates from Karimunjawa. NRPS were detected only in isolates SP 3-9, SH 3-4, KI 1-6, KI 2-2, KI 2-4. The secondary metabolite-encoding gene, PKS1, was detected in isolates SP 3-5, SP 3-8, KI 2-2. PKS II genes were detected only on isolates SP 2-4, SH 3-8, KI 1-6, KI 2-2, and KI 2-4. Isolate SP 3-5 was revealed as <italic>Pseudomonas aeruginosa</italic> (93.14%), isolate SP 2-4 was <italic>Zhouia amylolytica</italic> strain HN-181 (100%) and isolate SP 3-8 was <italic>P. aeruginosa</italic> strain QK -2 (100%).</p> </abstract>

The potential Two Types of Green Macroalgae (Caulerpa racemose and Caulerpa lentillifera) as a Natural Food Preservative from Jepara beach, Indonesia

“…The symbiotic bacteria identified in seaweed are Pseudoalteromonas arabiensis (CL21, 99.79 % and CR33, 100 %), Pseudoalteromonas piscicida (CL22, 99.78 % and CR31, 99.93 %), Pseudoalteromonas shioyasakiensis (CL33, 99.23 %), and Vibrio alginolyticus (CR44, 99.90 %), as stated in Table 6. The types of seaweed symbiont bacteria found are known to be found in sediments, such as Pseudomonas aeruginosa bacteria found in mangrove sediments [22]. In unextracted seaweed of Caulerpa, the composition mainly consists of water, carbohydrates, proteins, fiber, and minerals.…”

“…This is due to its ability to enhance shrimp's immune response, growth, and resistance to the pathogen Vibrio harveyi [32]. This bacterium has also been reported to have the potential for hydrolysis of Ulva lactuca polysaccharides [33].…”

“…Pseudomonas sp. bacteria are also frequently found in mangrove sediments, which have antibacterial properties [22].…”

Secondary Metabolites from Symbiotic Bacteria of Seagrass and Molluscs as A Reference for Natural Food Preservatives

“…Subsequently, a seagrass sample was extracted using maceration with n-hexane, ethyl acetate, and methanol solvents (1:5 w/v) (grammes of solute present in a volume of liquid solvent) each for 24 h [14]. The extraction results were tested using thin layer chromatography (TLC) [15] and phytochemical analysis. Furthermore, seagrass extract samples were tested for seagrass using gas chromatography-mass spectrometry (GC-MS) [15].…”

Antimicrobial agents and microbial ecology

“…Antimicrobials have been present in nature for much longer than their use by humans. The study of interactions between different microorganisms, whether prokaryotes or eukaryotes, is an important source of new antimicrobial discovery [16] – [20] . Ecological knowledge of antimicrobial production conditions, functions and roles in an ecosystem is necessary for the discovery of new antimicrobials and their safe and effective use.…”