This study evaluated the toxicological and antibacterial activity of crude extract of endophytic bacteria’s protein associated with the red algae Eucheuma spinosum which was produced at various incubation times. The external and internal proteins of the potential bacteria were collected on the incubation times which were 18, 24, 30, 36, 42, 48, and 54 hours. The evaluation toxicological of protein used Brine Shrimp Lethality Test (BSLT) method and the antibacterial activity of protein towards E. coli and S. aureus were measured using the diffusion method. Seven bacteria were successful to be isolated from these algae (ES01, ES11, ES21, ES22, ES23, ES24, and ES25), the Isolate ES25 was a genus of Vibrio and its protein had the potential to be produced. External protein levels were higher than internal, so it continued with the next phase. The extracted protein of (PE42) was active towards S. aureus (12.0 mm) while the extracted protein of (PE36) is active toward E. coli (9.0 mm) and also highly toxic to the larvae of Artemia salina Leach (1.596 μg/mL). The external protein of endophytic bacteria ES25 (Vibrio) associated with red alga Eucheuma spinosum was potentially produced in the time of incubation above 36 hours to get the highest toxicity and active antibacterial.

Protein fractions were isolated from red algae Eucheuma spinosum, this alga was derived from coast Takalar, Punaga Village, District Mangarabombang, Takalar. Protein fractions were macerated with Tris-HCl buffer. Ammonium sulfate was used to fractionation of proteins while determinations of protein content used Lowry method. The protein fractions were tested their activity against pathogenic bacteria. The fractions with the highest activity were combined with chloramphenicol and then was tested their activities back. The last test for protein fractions was screening toxicity; the method screening used Brine Shrimp Lethality Test (BSLT) method. The highest protein concentration on the crude extract was 96.76 mg/ml and the highest protein fraction concentration on a fraction of 20-40% (F2) was 88.42 mg/ml. The strongest protein fraction activity on a fraction 0-20% (F1) with inhibition zone is 9.09 mm to Escherichia coli bacteria and 9.56 mm to Staphylococcus aureus bacteria because the protein fraction F1 is highest so that it combined with chloramphenicol. All of a combination antibacterial activity was show an antagonistic effect against E. coli and S. aureus but did not for a combination of Protein Fraction F1: Chloramphenicol (95.35µg: 7.5µg), they shown additive effect (indifference) to S. aureus. The Protein fraction F1 from the Eucheuma spinosum algae was toxic to the Artemia salina Leach larvae; the value of LC50 was 7.252μg/mL. This fraction may be a potential anticancer drug agent, to prove it needs further research.

This study reported the protein bioactivity of two sponges Haliclona fascigera and Clathria reinwardti, collected from the waters of Kapoposang island of South Sulawesi in the search for potential new drugs. Protein extracts were subjected to antibacterial activity test and anticancer activity screening. Isolation of the protein fraction was carried out using a polar solvent (Tris-HCl buffer 0.1 M). Purification of protein was done by fractionation method using ammonium sulphate followed by dialysis and finally determination of protein content was carried out by Lowry method. An Antibacterial activity tests includes diffusion method using paper disc and anticancer activity screening with Brine Shrimp Lethality Test (BSLT). The results showed that protein from sponge Clathria reinwardtii (0-20% fraction) and sponge Haliclona fascigera (20-40% fraction) were effective in inhibiting the growth of Staphylococcus aureus and Escherichia coli bacteria, but not effectively as new antibacterial agents. The most toxic anticancer activity screening for shrimp larvae A. salina Leach was seen in the protein fraction of sponge Haliclona fascigera (20-40% fraction) with LC50 value = 0.013 μg/mL.

Proteins from microbes are a large source of potential raw material for novel pharmaceuticals. Endophytic bacteria associated with algae associated have been shown to be particularly promising candidates. In a previous study, a crude protein extract was isolated from an endophytic Vibrio sp. strain ES25. The extract was found to have anti-microbial activity. Despite these promising results, further work was needed to characterize both the protein and the bacteria that produce it. In this study, we sought to increase the activity of the previously discovered protein through pepsin digestion as well as provide sequence data to characterize the bacterial isolate. Here, we show promising evidence that the hydrolysate produced (QA1d) was found to have a promising antimicrobial as well as anticancer properties. Through the DNA sequencing, we also provide better taxonomic information on the isolate. Finally using Liquid Chromatography-Mass Spectroscopy/Mass Spectroscopy (LC-MS/MS) and in silico prediction, we identify to novel peptides produced from the bacterial protein that were predicted to have multifunctional activity. These results shown here indicate these peptides are promising candidates for anticancer drug development or antibacterial agents for the food industry.

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