Antje Labes

Objective: Calcium spirulan (CaSP) has been shown to prevent host cell penetration by several enveloped viruses, including Herpes simplex virus type 1 (HSV-1), in in vitro experiments. We investigated how CaSP inhibits HSV-1 penetration into human keratinocyte cells by studying the interactions among CaSP, HSV-1, and keratinocytes in vitro . Methods: After chemical characterization of the CaSP, we conducted two separate experiments. First, we added different HSV-1 viral loads to HaCaT cells that had been incubated with CaSP for 3 h. Second, different viral loads were incubated with CaSP for 3 h and then the resulting mixtures were added to the cells. The incubation period lasted 48 h. The HSV-1 median tissue culture infectious dose (TCID ₅₀ ) was determined by measuring the cytopathic effect (CPE) index and using a colorimetric immunohistochemical (IHC) staining. CaSP degradation and penetration into keratinocytes were determined using an HLPC method developed in house. Results: CaSP was detected in the supernatant but not in the cells. After pre-incubating the cells with CaSP, a viral load of 4.56 TCID ₅₀ was inhibited by concentrations of ≥50 µg/mL of CaSP after 48 h of incubation (CPE ≤2). An activity against the highest HSV-1 TCID ₅₀ (114) was observed only with 800 µg/mL of CaSP. Similar effects were observed after 48 h pre-incubation of HSV-1 with CaSP when ≥50 µg/mL of CaSP was added to a viral suspension of 4.56 TCID ₅₀ . The higher viral load (TCID ₅₀ 114) was not inhibited. Sustained inhibition of all HSV-1 titers used (from 0 to 1000 TCID ₅₀ ) was observed only at a CaSP concentration of 800 µg/mL, independent from the pre-incubation method. Conclusion: CaSP does not enter keratinocytes and seems to interact with both cells and virus as viral inhibition was independent from the preincubation method.

Puspitasari E, Senjarini K, Dewanti IDAR, Febrianti V, Hasanah FM, Labes A. 2025. Culturable marine fungal biodiversity from the south coast of Jember, East Java, Indonesia. Biodiversitas 26: 3000-3010. Marine fungi with their unique environment are a promising source for drug discovery. Their distinct natural products, different from those of terrestrial fungi, give them potential bioactivity. However, not all marine fungi are culturable. This research aimed to determine the biodiversity of culturable marine fungi from Jember south coast, East Java, Indonesia. The sampling was conducted on samples available on the Jember south coast, East Java, Indonesia, including seawater, sand, wood remains, green algae, and red algae. The isolation of marine fungi using fungal basal media. Once a single colony with different morphotypes was obtained, it was characterized based on its morphology (macroscopically and microscopically using bright field and scanning electron microscope) and molecularly. The fungal morphological features were described based on the colony’s and cell’s appearance. The molecular characteristics were carried out using DNA barcoding based on the internal transcribed spacer. The results revealed 17 isolates of culturable marine fungi from Jember south coast. They were dominated by the genus Penicillium (47.059%), followed by Scopulariopsis and Curvularia (17.647%), Aspergillus (11.765%), and Cladosporium (5.882%); members of phylum Ascomycota. The results showcase the rich diversity of species that have potential as drug candidates. Further studies are needed to reveal their bioactivity.

Marine bacteria and fungi have been known as sources of drug candidates. Novel natural products discovery derived from marine bacteria and fungi has been boosted in the last decades. This review discusses the challenges of culturing marine bacteria and fungi taken from their natural habitat into laboratory-scale culturable ones. Since, not all bacteria and fungi, when they are taken from their natural habitat and grown in a laboratory setting, are culturable. This review will also discuss possible solutions to overcome those challenges. Targeted bioactivity relies on the marine bacterial and fungal growth, especially due to the capability on producing the intended natural products. From this review, some important factors that must be taken into consideration to have optimal bacterial and fungal growth are genes and their variation in a species, media composition, and growth condition.

BACKGROUNDAnopheles (An.) sp. transmits Plasmodium parasites that cause malaria. In its life cycle in the mosquito’s body, Plasmodium passes through 2 mosquito organs, namely the salivary glands and midgut. The bacterial community (symbiont bacteria) in these organs has been known to influence and/or inhibit the development of the Plasmodium life cycle by producing specific proteases. This research aims to isolate and characterize symbiotic bacteria with proteolytic activity from 2 important malaria vectors in Indonesia: An. sundaicus and An. vagus. METHODSA total of 183 bacterial originating from the salivary glands and midgut were successfully isolated. Initial screening was carried out based on morphological differences, followed by purification of the selected isolates to obtain single colonies. The selected isolates were then subjected to an initial proteolytic ability test using skim milk agar media. Only isolates with proteolytic activity were further characterized with the 16SrDNA molecular marker. The isolates were pabs5 from the salivary glands and pabs3 from the midgut of An. vagus, while pdbs3 and ecbs4 were isolates from the salivary glands and midgut of An. sundaicus. RESULTSMorphological and molecular characterization showed that both pabs5 and pabs3 isolates were Pseudomonas(Ps.) aeruginosa, while ecbs4 was Enterobacter cloacae and pdbs3 was Pantoea dispersa. These species werefirst discovered in Anopheles vagus and Anopheles sundaicus. CONCLUSIONThe ability of Ps. aeruginosa and Pantoea dispersa to produce proteases indicated their potential role in the exploration of new strategies to control mosquito vectors that transmit pathogens.

Ijen Geopark is one of the UNESCO Global Geoparks in Indonesia. The Erek-erek Geoforest (EEG) is one of the biosites in the Ijen Geopark. The EEG has an abundant biomass which is composed of lignocellulosic complex. The abundance of biomass has the potential as a source of lignocellulolytic microorganisms that can degrade lignocellulose material. The purpose of this research was to isolate lignocellulolytic bacteria from the Erek-erek Geoforest. This research method was soil sampling, physicochemical analysis of soil, isolation, and purification of bacteria, growth capability in lignocellulose media, and pathogenicity-test. The results showed that a total of 180 were isolated from EEG. There are 93 bacteria growth in lignin media and 142 bacteria growth in cellulolytic with the isolated code EIB (erek-erek Ijen Banyuwangi) under aerobic conditions which had various bacterial morphologies. To ensure the safety of using these isolates, it is necessary to do a pathogenicity test of these bacteria using a blood agar plate. Indicated pathogenic bacteria will form a clear zone around the bacterial colony on the blood media. The pathogenicity test of the highest lignocellulolytic bacteria showed that the 3 ligninolytic and 3 cellulolytic EIB bacteria isolates were non-pathogenic. Further, non-pathogenic bacteria from the soil litter of erek-erek forests can be tested for their potential as biological agents for the industry.

Bioprospecting of the marine environment for drug development has gained much attention in recent years owing to its massive chemical and biological diversity. Drugs for the treatment of skin and soft tissue infections have become part of the search, mainly with respect to enlarging the number of available antibiotics, with a special focus on multidrug-resistant Gram-positive bacteria, being the major causative agents in this field. Marine resources offer novel natural products with distinct biological activities of pharmaceutical importance, having the chance to provide new chemical scaffolds and new modes of action. New studies advance the field by proposing new strategies derived from an ecosystemic understanding for preventive activities against biofilms and new compounds suitable as disinfectants, which sustain the natural flora of the skin. Still, the development of new compounds is often stuck at the discovery level, as marine biotechnology also needs to overcome technological bottlenecks in drug development. This review summarizes its potential and shows these bottlenecks and new approaches.

Despite advancements in RNA extraction methods, RNA extraction from sources rich in polyphenols and polysaccharides such as algae and seagrasses remains a challenge. Here we present a RNA extraction strategy using a hexadecyltrimethylammonium bromide (CTAB) extraction buffer and demonstrate its effectiveness on a broad range of red, green, and brown algae, as well as on the cyanobacterium Arthrospira platensis and the seagrass Zostera marina. For the vast majority of tested samples we achieved high yields of RNA comparable to those obtained from higher plants by commercially available kits (ranging from 3.9 to 125.9 µg RNA g⁻¹ fresh weight). Analysis by UV/Vis spectrometry and capillary electrophoresis revealed high purity and integrity of obtained RNA extracts. For highly challenging species of brown algae like Fucus vesiculosus, Fucus serratus and Dictyosiphon foeniculaceus, we established an alternative procedure using a sodium dodecyl sulfate (SDS) extraction buffer in combination with a commercial kit. With this protocol, even higher RNA yields up to 317.0 µg g⁻¹ fresh weight were extracted from polysaccharide-rich brown algae tissues. This study can serve as a guideline and starting point for the development of RNA extraction protocols for so far unstudied algal species from very diverse taxa.

Editorial: Marine microbial-derived molecules and their potential medical and cosmetic applications, volume II

Carotenoids and squalene are important terpenes that are applied in a wide range of products in foods and cosmetics. Thraustochytrids might be used as alternative production organisms to improve production processes, but the taxon is rarely studied. A screening of 62 strains of thraustochytrids sensu lato for their potential to produce carotenoids and squalene was performed. A phylogenetic tree was built based on 18S rRNA gene sequences for taxonomic classification, revealing eight different clades of thraustochytrids. Design of experiments (DoE) and growth models identified high amounts of glucose (up to 60 g/L) and yeast extract (up to 15 g/L) as important factors for most of the strains. Squalene and carotenoid production was studied by UHPLC-PDA-MS measurements. Cluster analysis of the carotenoid composition partially mirrored the phylogenetic results, indicating a possible use for chemotaxonomy. Strains in five clades produced carotenoids. Squalene was found in all analyzed strains. Carotenoid and squalene synthesis was dependent on the strain, medium composition and solidity. Strains related to Thraustochytrium aureum and Thraustochytriidae sp. are promising candidates for carotenoid synthesis. Strains closely related to Schizochytrium aggregatum might be suitable for squalene production. Thraustochytrium striatum might be a good compromise for the production of both molecule groups.