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This study aims to isolate and characterise the Pink Pigmented Facultative Methylotrophs (PPFM) bacteria from the leaves of common Malaysian table salad (ulam). The colonies of PPFM bacteria were obtained using selectively modified Pseudomonas agar based on the appearance of the pink pigment colony. The three selected isolates labelled OJ4, OJ154 [Oenanthe javanica (Blume) DC.] and ML8 [from Melicope lunu-ankenda (Gaertn.) T. G. Hartley] were chosen for characterisation. The result showed the PPFM bacteria colonies (log CFU/g) at the leaf surface of C. caudatus are 4.4 ± 0.1, significantly higher than O. javanica, 3.8 ± 0.2, and M. lunu-ankenda, 3.2 ± 0.1. The selected isolates belong to the Gram-negative group, motile with rod shape with size [length (l) × width (w)] in µm unit 4.3 ± 1.1 × 1.6 ± 0.6, 5.4 ± 0.2 × 1.2 ± 0.1, and 3.5 ± 0.7 × 1.0 ± 0.0, respectively. They show positive urease, catalase, and oxidase activities, while none of them can degrade starch, gelatine, or cellulose, as well as glucose fermentation (MR test) and metabolism actions (VP test), producing indole and hydrogen sulphide gaseous. Only isolate OJ154 demonstrates positive casein hydrolysis and nitrate reduction activities, while only isolate ML8 can utilise citrate but not in lipid degradation. Their sequence analysis of the 16S rRNA indicated that OJ4 and ML8 are Methylobacterium radiotolerans with a similarity of 99%, whereas, OJ154 is Methylorubrum salsuginis with a similarity of 99%. To conclude, PPFM bacteria from the leaves of C. caudatus, O. javanica, and M. lunu-ankenda have been isolated and characterised in particular. [ABSTRACT FROM AUTHOR]

Various microorganisms can grow in egg-based food products, and yeast is among the microorganisms that thrive in egg products. Yeasts naturally produce large enzymes by breaking down organic materials during growth. Yeast has a great biotechnological potential owing to its extracellular enzymatic activity. Therefore, it is important to study yeast species, especially those from food sources and the environment. Protease production and activity are affected by various factors such as temperature, time, and pH. In this study, 47 yeast isolates were identified and purified from traditionally processed Indonesian duck eggs via repeated sub-culturing and quadrant streaking. Screening of the yeast isolates on skim milk agar medium showed that 23 isolates exerted proteolytic activity, whereas the remaining 25 did not. Yeast isolates with proteolytic capabilities belonged to the Saccharomyces, Pichia, and Candida genera. The highest protease activities were observed in isolates TA-17 and TPi-08, with activity values of 0.618 and 0.098 U/mL, respectively. [ABSTRACT FROM AUTHOR]

Sesame seed dregs or residue refers to the byproduct that is left after sesame seeds have been processed to extract oil and can used in a variety of ways. The residues were subjected to spontaneous fermentation for 7 days at room temperature (23-27°C). The purpose of this research was to analyze antimicrobial and antioxidant activity of ethanolic extract obtained from fermented black sesame seed dregs. The diameter of inhibition zones of extracts against 16 pathogenic microorganisms ranged from 6.88 to 11.00 mm and the minimum inhibitory concentrations ranged from 6.25 to 50.00 mg/mL, with the extract being particularly effective against P. aeruginosa ATCC9027 and C. albicans ATCC10231. Minimum bactericidal/fungicidal concentrations were spread from 25.00 to >50.00 mg/mL. P. aeruginosa ATCC9027 and C. albicans ATCC10231 were completely killed in 2 h incubation time at 4 × MIC in a time-kill kinetics assay. In comparison to raw seeds and seed dregs extracts, the fermented seed dregs extract displayed a higher total phenolic content. In addition, the fermented extract had a lower IC50 concentration compared to raw seeds and seed dregs extracts. These results suggest that fermented black sesame seed dregs can be used as an alternative method to reduce the microorganism's growth. This is crucial for ensuring food safety and minimizing the risk of foodborne poisoning. [ABSTRACT FROM AUTHOR]

Microorganisms such as Pseudomonas aeruginosa have always been adaptable in surviving the harsh environment such as antimicrobial agents via the quorum sensing (QS) mechanism. Studies have shown that quorum sensing mechanism cases have been highly associated with foodborne illnesses. Since synthetic compounds such as azithromycin (AZM) are reported to have detrimental effects on human, using medicinal local plants have been gaining attention as an anti-quorum agent. The aim of this study was to determine the anti-quorum sensing activity of the Curcuma xanthorrhiza Roxb. extract against P. aeruginosa ATCC35554 quorum sensing system including swarming motility, pyocyanin production and biofilm formation. The results indicated that the extract required a high concentration to inhibit and kill the P. aeruginosa with minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC) values of 200 and >700 mg/mL, respectively. Thus, anti-quorum sensing assays were done in concentration up to 200 mg/mL. The inhibition of quorum sensing activity of C. xanthorrhiza Roxb. extract on P. aeruginosa quorum sensing was concentration dependent manner. At 200 mg/mL of the extract exhibited 72.12% reduction of swarming motility, 84.30% inhibition of the pyocyanin production and 78.35% reduction in the biofilm formation. In conclusion the crude extract of C. xanthorrhiza Roxb. extract has ability to reduce the virulence factors; swarming motility, pyocyanin production and biofilm formation regulated by quorum sensing. Thus, the extract C. xanthorrhiza Roxb. extract has anti-quorum sensing or quorum quenching activity. [ABSTRACT FROM AUTHOR]