Abstract. Marzuki I, Kamaruddin M, Ahmad R. 2021. Identification of marine sponges-symbiotic bacteria and their application in degrading polycyclic aromatic hydrocarbons. Biodiversitas 22: 1481-1488. Diverse and abundant microbial species that occupy marine sponges may make important contributions to host metabolism. Sponges are filter feeders and devour microorganisms from the seawater around them. Each microbe that endures the sponges’ digestive and immune responses are related symbiotically. Marine sponges symbiont bacteria can comprise as much as 40% of sponge tissue volume, and these are known to exhibit a great potential on polycyclic aromatic hydrocarbons (PAHs) degradation. However, the potential use of marine sponges symbiont bacteria is unexplored. Therefore, we designed and conducted a study to identify bacterial isolates obtained from sponges. For this, we collected sponges samples (Hyrtios erectus, Clathria (Thalysias) reinwardti), Niphates sp., and Callyspongia sp.) from the Spermonde islands in Indonesia. We successfully found eight bacterial isolates from four sponges, as molecular identification based on 16S rRNA approach revealed bacterial isolates of SpAB1, SpAB2, SpBB1, SpDB1, and SpDB2 from three sponges (Hyrtios erectus, Clathria (Thalysias) reinwardti), Niphates sp.). Interestingly, these were closely related to Pseudomonas, and a bacterial isolate from Callyspongia sp. (SpCB1) showed similarity to Bacillus. Bacillus and Pseudomonas bacteria isolated from hydrocarbon-contaminated sponges exhibited degradation of naphthalene and pyrene PAHs.

Every petroleum-processing plant produces sewage sludge containing several types of polycyclic aromatic hydrocarbons (PAHs). The degradation of PAHs via physical, biological, and chemical methods is not yet efficient. Among biological methods, the use of marine sponge symbiont bacteria is considered an alternative and promising approach in the degradation of and reduction in PAHs. This study aimed to explore the potential performance of a consortium of sponge symbiont bacteria in degrading anthracene and pyrene. Three bacterial species (Bacillus pumilus strain GLB197, Pseudomonas stutzeri strain SLG510A3-8, and Acinetobacter calcoaceticus strain SLCDA 976) were mixed to form the consortium. The interaction between the bacterial consortium suspension and PAH components was measured at 5 day intervals for 25 days. The biodegradation performance of bacteria on PAH samples was determined on the basis of five biodegradation parameters. The analysis results showed a decrease in the concentration of anthracene (21.89%) and pyrene (7.71%), equivalent to a ratio of 3:1, followed by a decrease in the abundance of anthracene (60.30%) and pyrene (27.52%), equivalent to a ratio of 2:1. The level of pyrene degradation was lower than that of the anthracene due to fact that pyrene is more toxic and has a more stable molecular structure, which hinders its metabolism by bacterial cells. The products from the biodegradation of the two PAHs are alcohols, aldehydes, carboxylic acids, and a small proportion of aromatic hydrocarbon components.

The purpose of this research is to understand sponge species, micro symbiont, performance, mechanisms, and types of compounds resulting from biodegradation. The analytical method is applied by selecting the model, results from characterization and morphological identification, phenotype, genotype. Selected of micro symbiont are made as suspensions, interacted with modified naphthalene contaminated waste. The biodegradation process using the Bacillus Sp (BS) isolates sponge Neopetrosia Sp and Acinetobacter Calcoaceticus (AC) isolated from sponge Callyspongia Aerizusa, was carried out by interacting a microscopic suspension of 5,000 mg/L naphthalene waste for 25 days. Micro symbiont biodegradation results by determining the concentration of contaminants and biodegradation products, in the form of pure organic compounds using GC-MS, and the analysis of functional groups of natural components using IR. Destruction of the naphthalene molecule occurs through an enzymatic reaction mechanism, observed based on visible parameters. The performance of BS symbiont biodegradation on naphthalene is in the range of 7.34% - 51.37%, while the AC range is 5.84% -37.26% in w/v, achieved within 5-25 days interaction. Biodegradation products based on functional groups were identified as compounds of aldehyde, ketone, carboxylic acids, esters, alkanes. Observation of biodegradation parameters confirmed pH changes, increased optical density values, gas bubbles formed and the smell of fermentation.

Sponge is often used as a bio indicator and bio monitoring in determining the level of heavy metal contamination in the sea. The purpose of this research is to analyze the destruction of PAHs and the reduction of heavy metal toxicity. Biodegradation and bio-adsorption occur with a 30-day interaction between bacterial symbiont sponge suspension against modified liquid waste containing a mixture of PAHs (naphthalene) contaminants, heavy metals Cr (VI) and Cd (II). The period of interaction of bacteria with heavy metals for 15 days, bio-adsorption power was determined using AAS, while the interaction with PAHs, the level of biodegradation was measured using GC-MS and Infrared Spectrophotometer. The results achieved bacteria BP and PS, have biodegradation and bio-adsorption activities against extreme waste contaminated with a mixture of naphthalene and heavy metal. The level of biodegradation of BP bacteria to naphthalene is weaker than PS bacteria. The bio-adsorption power of PS bacteria is higher for Cr (VI) and Cd (II) ions. The components of naphthalene in extreme waste inhibit the bio-adsorption performance of BP and PS bacterial, conversely there is an effect of inhibition of bacterial activity on the biodegradation process of naphthalene by the presence of heavy metals.

The activities of the petroleum processing industry and marine transportation potentially cause of hydrocarbon pollution. It is assumed that every water area exposed to hydrocarbons also found bacterial species that have biodegradation properties against PAH contaminants. This study aims to analyze the relationship between biodegradable bacteria and the status of marine waters exposed to hydrocarbons. The method of analyzing the type of PAH contaminants for each seawater and sponge samples were processed at 4 different points using GC-MS, the same sample was also carried out isolation, characterization and activity test of bacterial isolates against naphthalene and pyrene type PAH. The analysis showed that the four samples of seawater were contaminated with hydrocarbons. The type of hydrocarbons found in each sample is different and the concentration value varies. The types of bacteria identified in seawater and sponge samples also varied. There were 8 types of isolates selected, each one isolate per sample, all of which showed biodegradation activity against hydrocarbon contaminants, while the order of aromatic contamination levels at the four sampling points Sp. 1 > Sp.2 > Sp.3 > Sp.4. These results indicate that the presence of biodegradable bacteria in water areas can be a bio-indicator for the presence of PAH pollutants.