Listeriosis is a severe foodborne illness characterized by a fatality rate exceeding 30%, attributed to the pathogen Listeria monocytogenes. This study evaluated 160 lactic acid bacteria (LAB) isolated from Thai pickled crabs for their potential as agents against L. monocytogenes and for their probiotic properties and probiogenomic characteristics. Among these strains, strain DRC3-2 exhibited activity through the synthesis of bacteriocin DRC3-2, which significantly inhibited L. monocytogenes ATCC 19115 in spot-on-lawn assays. Phenotypic and whole-genome analyses revealed that strain DRC3-2 thrived in environments with 2-6% NaCl, pH values ranging from 3 to 9, and temperatures between 25 and 45°C. Based on average nucleotide identity (ANI) and digital DNA‒DNA hybridization (dDDH) values, strain DRC3-2 was taxonomically classified as Lactococcus lactis subsp. hordinae. The production of bacteriocin DRC3-2 peaked during the late stationary phase, following its synthesis in the early exponential growth phase. BAGEL4 analysis identified the putative novel bacteriocin DRC3-2 as lactococcin A and B, with respective bit-scores of 40.05 and 36.58. In silico safety assessments confirmed the nonpathogenic nature of strain DRC3-2 in humans, highlighting its absence of antibiotic resistance genes. Finally, this investigation underscores the novel bacteriocin DRC3-2 for application in the prevention and treatment of L. monocytogenes infections.
Listeria monocytogenes เป็นเชื้อก่อโรคที่มักพบในอาหารที่มีการปนเปื้อน สามารถอยู่รอดในสภาวะที่รุนแรง เช่น อุณหภูมิต่ำ ความเป็นกรดสูง ความเข้มข้นของเกลือสูง ซึ่งทำให้มีความเสี่ยงอย่างมากในระบบย่อยอาหารของมนุษย์ ดังนั้นจึงศึกษาแบคทีเรียกรดแลคติกที่มีความสำคัญในอุตสาหกรรมอาหารและยาเนื่องจากมีคุณสมบัติเป็นโพรไบโอติก และแบคทีเรียกรดแลคติกบางชนิดที่สามารถผลิตแบคเทอริโอซินหรือเปปไทด์ต้านจุลชีพที่มีฤทธิ์ทางชีวภาพ และแบคเทอริโอซินที่มีประสิทธิภาพในการยับยั้งแบคทีเรียก่อโรค ซึ่งถือว่าเป็นทางเลือกที่น่าสนใจแทนการใช้ยาปฎิชีวนะแบบดั้งเดิม เนื่องจากช่วยลดการพัฒนาการดื้อยาของแบคทีเรีย นอกจากนี้แบคเทอริโอซินยังมีความเสถียรสูง สามารถทนต่ออุณหภูมิที่รุนแรงและสภาวะเป็นกรดได้ อีกทั้งยังไม่เป็นพิษต่อเซลล์มนุษย์ การศึกษานี้จึงมุ่งหมายเพื่อศึกษาแบคเทอริโอซินชนิดใหม่จาก Lactococcus lactis subsp. hordinae DCR3-2 ซึ่งแยกได้จากปูดอง เพื่อประเมินฤทธิ์การต้านจุลชีพของแบคทีเรียชนิดนี้ และการวิเคราะห์ทางbioinformatics เพื่อยืนยันว่าสายพันธุ์ DCR3-2 มีความปลอดภัยสำหรับมนุษย์และมีคุณสมบัติโพรไบโอติก
คณะวิทยาศาสตร์
Sugar production from sugarcane is a complex process that requires precise control. One of the major issues is sugar loss, which can result from various factors, particularly "burnt cane," before being sent to the mill. This affects the quality of the sugarcane and the efficiency of sugar extraction, along with the performance of the machinery and the properties of the cane, which impact the amount of sugar extracted. This study aims to analyze the factors that influence sugar loss in the sugar production process, using quantitative data from a sugar factory. Nine variables were examined, including mechanical efficiency, machine downtime per day, cane waiting time per day, sand content in cane juice, pol extraction efficiency, overall working time efficiency, cane juice purity, cane sugar content (C.C.S.), and burnt cane. The data were analyzed using correlation analysis to examine relationships between variables and regression modeling to predict sugar loss. The results showed that mechanical efficiency, cane sugar content, and the amount of sand or impurities in the cane juice were significantly correlated with sugar loss. Mechanical efficiency had a direct relationship with the amount of cane milled, which improved sugar production. On the other hand, burnt cane, or cane that was burnt before harvesting, resulted in reduced sugar extraction and impacted the quality of the sugar. Therefore, reducing sugar loss in the production process can be achieved by improving machine efficiency, reducing impurities in cane juice, and managing burnt cane, which will improve sugar production efficiency in the future.
วิทยาลัยนวัตกรรมการผลิตขั้นสูง
This research presents a Wilkinson power divider using a common inductor. The lumped topology uses the inherently inductive loss of the inductor as a part of the design, so the conventional resistor for high isolation can be omitted. Therefore, low-loss and high-isolation performances of the compact circuit were achieved. The proposed 2.5-GHz divider was implemented on a silicon-based integrated passive device process. Measurement of the prototype chip had a reflection coefficient below 18 dB at all ports, an insertion loss of 0.5 dB and isolation above 28 dB. The chip size is merely 0.011 wavelength x 0.019 wavelength.
วิทยาลัยนวัตกรรมการผลิตขั้นสูง
Since organic rice storage silos were faced with an insect problem, an owner solved this problem using the expert system (ES) in the controlled atmosphere process (CAP) under the required standard, fumigating insects with an N2, reducing O2 concentration to less than 2% for 21 days. This article presents the computational fluid dynamics (CFD) assisted ES successfully solved this problem. First, CFD was employed to determine the gas flow pattern, O2 concentration, proper operating conditions, and a correction factor (K) of silos. As expected, CFD results were consistent with the experimental results and theory, assuring the CFD’s credibility. Significantly, CFD results revealed that the ES controlled N2 distribution throughout the silos and effectively reduced O2 concentration to meet the requirement. Next, the ES was developed based on the inference engine assisted by CFD results and the sweep-through purging principle, and it was implemented in the CAP. Last, the experiments evaluated CAP’s efficacy in controlling O2 concentration and insect extermination in the actual silos. The experimental results and owner’s feedback confirmed the excellent efficacy of ES implementation; therefore, the CAP is effective and practical. The novel aspect of this research is a CFD methodology to create the inference engine and the ES.