A strain of Bacillus bacteria, which was able to increase the molecular weight (M) of black liquor (BL) lignin through polymerization, enabling the subsequent industrial use of lignin, was isolated and characterized. This study is believed to be the first time that actual bacteria cells, rather than pure laccase, have been used to polymerize BL lignin. Black liquor is a toxic waste product from the pulp and paper industry that contains lignin. However, the M of lignin is too low for commercial use. The bacteria performed two processes. First, the bacteria produced laccase, which degraded lignin into low M aromatic compounds (LMWACs). Second, the laccase transformed the LMWACs into quinone intermediates, which polymerized and became high M lignin. Five bacterial strains were isolated from a pulp mill, and the best strain was selected. The optimum growing conditions and BL concentration were determined. The optimum growth conditions when using pure lignin were 1 g/L lignin, 5 g/L urea, and 35 °C. When using BL instead of pure lignin, the optimum concentration was 2% BL (v/v). This information could help develop effective industrial utilization of BL lignin.

Nowadays, most people are more concerned with their personal health. Salads that are ready to eat are frequently a healthy eating option. It is consumed raw and unheated, which promotes the growth of numerous microorganisms. Furthermore, microbial contamination may occur because of the use of contaminated water for cleaning and packing. Aeromonas spp. are bacteria that grow on the water’s surface. They can survive in water that has been chlorinated to eliminate bacteria, which is critical for public health. Because bacteria can produce and secrete a variety of enzymes that are toxic to human tissue, there are a number of factors that contribute to violence. In people with low immunity, the majority of them can cause serious disease. As a result, the goal of this research is to look into and identify Aeromonas spp. isolated from ready-to-eat salad. The 16s rDNA gene was used to confirm the findings, and a PCR was used to look into the virulence factor genes. In this study, 9 isolates of Aeromonas spp. were found in 136 ready-to-eat salad samples, accounting for 6.6 percent of the total. Six virulence genes (ast, fla, lip, act, alt, and aphB) were used to identify each of 9 isolates where fla were found 4 isolates (44.44 %), and ahpB were also discovered 8 isolates (88.88 %). Therefore, there is the potential that ready to eat salad can be contaminated by Aeromonas spp. containing virulence factor which can cause a severe health risk such as diarrhea to consumers.

Background Staphylococcus aureus is one of the most common pathogens responsible for food poisoning due to its ability to produce staphylococcal enterotoxin (SE). S. aureus can form biofilms on the surfaces of food processing devices, enabling the distribution of SE on foods through cross-contamination events. Thailand is known for its exotic cuisine, but there is no data on the prevalence of SE-harboring S. aureus in restaurants in Thailand. Methods In this study, we conducted surface swabs on surfaces of kitchen utensil that come into contact with food and on the hands of food handlers working in restaurants in the north part of Thailand. Isolated S. aureus was investigated for biofilm formation, virulence, and SE genes. Results Two hundred S. aureus were isolated from 650 samples. The highest prevalence of S. aureus contamination was detected on the hands of food handlers (78%), followed by chopping boards (26%), plates (23%), knives (16%), spoons (13%), and glasses (5%). All of them were methicillin-sensitive S. aureus (MSSA) and the mecA gene was not present in any strains. Biofilm formation was detected using the CRA method, and 49 (24.5%) were identified as biofilm-producing strains, with the hands of food handlers identified as the primary source of biofilm-producing strains. The prevelence of biofilm-related adhesion genes detected were: icaAD (13%), fnbA (14.5%), cna (6.5%), and bap (0.5%). Two classical enterotoxin genes, sec and sed, were also found in four and six of the S. aureus isolates, respectively, from hands and utensils. Conclusion The highest prevelence of S. aureus was detected on the hands of food handlers. S. aureus strains with biofilm and enterotoxin production abilities were discovered on food contact surfaces and the hands of food handlers, implying significant risk of food contamination from these sources that could be harmful to consumers. To avoid cross-contamination of food with food contact items, the food handlers’ hands should be properly washed, and all food preparation equipment should be thoroughly cleaned.