Studies on an Indigenous Probiotic (<i>Shewanella algae</i>) Isolated from Healthy Shrimp Intestine
Bibliographic record
Abstract
An indigenous probiotic ( Shewanella algae ) previously isolated from healthy shrimp ( Penaeus monodon ) intestine and found to protect Clarias gariepinus from Aeromonas hydrophila infection was screened for antibiotic susceptibility, enzymatic activities and abiotic stress tolerance. Optimization of the cultivation conditions and identification of its bioactive compounds were also carried out. The antibiotic susceptibility was performed by disk diffusion method. A total of fifteen antibiotic discs were employed. Qualitative screening for extracellular enzyme-producing ability was done using skim milk agar, starch agar, egg yolk agar, gelatin agar and cellulose agar for protease, amylase, lipase, gelatinase and cellulase activities respectively. The optimal conditions for growth of the isolate were assessed by growing on nutrient broth at various pH, temperature and salinity levels. Cell growth was estimated by standard plate count. The probiotic was screened for antimicrobial activity by agar well diffusion assay against the pathogen ( Aeromonas hydrophila ) using cell-free supernatant (crude extract) and methanolic extract. The methanolic extract was analyzed using gas chromatography- mass spectrometry (GC-MS). The isolate showed a wide range of environmental tolerance with pH (4-11), temperature (28-40℃) and salinity (0-100 ppt). The optimum conditions for cell growth were pH 6-8, temperature 37℃ and salinity 5-15 ppt. The isolate was susceptible to all tested antibiotics which supported the ideal probiotic characteristic. The isolate was capable of producing extracellular enzymes such as protease, amylase, lipase and gelatinase which could improve feed digestibility and feed utilization. The crude and methanolic extracts were active against the pathogen with inhibition zones of 13.0 ± 0.02 mm and 18.0 ± 0.03 mm respectively. Two bioactive compounds (Tromethamine and Pyrrolo [1, 2-a] pyrazine-1, 4-dione, hexahydro-) were identified. These results suggest that the Shewanella algae could probably be used as a potential probiotic in aquafeed formulation and a good source of novel drug development.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".