This study employed Bacillus spp. with α-amylase production isolated from Malaysian hot spring for domestic kitchen food waste treatment contained grains, vegetables, chicken and tuna that mimic the food waste discharge from domestic kitchens in Malaysian household. Results showed that Bacillus licheniformis HULUB1 and Bacillus subtilis SUNGB2 possess excellent amylolytic properties. Highest α-amylase activity was obtained when both isolates were cultivated at pH 6.0 and 65 C with concentrations of 18.15 U/mL for HULUB1 and 22.14 U/mL for SUNGB2. Stability of α-amylase with significant levels of enzyme activity were recorded at 55-85 C and pH 5.0-9.0. The extracted mixed α-amylase of HULUB1 and SUNGB2 showed greatest reduction were achieved at day 12 with 45% AE 0.03 solid content at 65 C. While the mixed culture of HULUB1 and SUNGB2 displayed an enhanced effect on the food waste contents reduction with 43% AE 0.02 solid content at 45 C after day 12. The findings showed that the combination of the two Bacillus spp. isolates possessed degradation of food wastes at faster rate than α-amylase. It was also pointed out that the standard food waste (SFW) and the treatment process assimilated for this study was suitable for the growth of Bacillus spp.

The purpose of the study was to elucidate the effect of preparation methods hard-boiled half-boiled & raw on the digestibility of protein and the amino acid composition as well as the protein quality of nutrient enriched Malaysian eggs. The amino acid content was determined using HPLC. All The essential and the non-essential amino acids as well as the individual amino acid was significantly increased as result of half-boiled and decrease as result of hardboiled methods. The PH value of hard-boiled, half-boiled & raw were 7.03±0.09, 6.795±0.06, 7.305±0.13 respectively, whereas the casein scores 5.53±0.04 as the lowest PH value. In vitro digestibility of protein value of hard-boiled, half-boiled & raw were 76.24±2.8, 81.54±1.8, 70.03±4.4 respectively, whereas the casein scores 99.08±2.4 as the highest digestibility value. Among the eggs samples, half-boiled had the highest digestibility at 81.54±1.8, followed by hard-boiled at 76.24±2.8. Whereas, the raw egg had the lowest digestibility value at 70.03±4.4. Based on these results there were significant differences (p < 0.05) among the egg samples compare to casein.

Extreme environments have been the interest of numerous studies and scientific publications. For many years, these environmental roles, which are characterised by high or low temperatures, high-pressure, low pH, high salt concentrations and companions of two or more extreme parameters. For many years, these environmental niches have increased in importance due to extreme microorganisms diversity and their potential returns of several industrial production processes concerning the food fields, medical and pharmaceutical. At present, it's possible to detect life in most extreme environments, from the deep sea hot springs, depth of the oceans, deep inside the earth crust, harsh chemical environments, and high radiation environments through metagenomics analysis. In this review, newly identified microorganisms, and their potential uses in several applied fields have been outlined. The microbial development in biofilms form has supported the survival of alkaliphiles, psychrophile, halophile thermophile and extremophile microorganisms; where they flourish due to the adaptation strategies involving complex variation in biofilms structure and behaviours.

Aims: Dental caries is a chronic infectious disease caused by Streptococcus mutans due to its ability to form biofilm. This study aims to assess the antimicrobial efficacy of Melastoma malabathricum leaf extract against S. mutans on the surface of tooth samples as a potential therapy for dental caries. Methodology and results: Extraction of M. malabathricum leaves was done using acetone as the solvent and antibacterial activity of the extracts was determined by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Antibiofilm activity of M. malabathricum extract against S. mutans was determined by comparing the colony count, biofilm formation assay and morphology observation by scanning electron microscope (SEM). The MIC value of extracts was 6.25 mg/mL and MBC value was >25 mg/mL. A decrease in colony count was noted when tooth samples were incubated with M. malabathricum extract for 8 h compared to 4 h incubation. At pH 5, the formation of the colony was the least, medium at pH 8 and maximum at pH 7. A decrease in biofilm formation was observed when tooth samples were incubated with the extract for 8 h. SEM observations showed treatment with the extract caused S. mutans cell membrane to leak leading to cell morphology changes. Conclusion, significance and impact of study: Acetone extract of M. malabathricum leaves showed excellent antibacterial activity against S. mutans. It has bactericidal activity with the ability to inhibit biofilm in dose-dependent manner against S. mutans. The morphological analyses suggested that the extract disrupted the cell membrane of the bacteria.

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