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
คณะอุตสาหกรรมอาหาร
Coffee is a critical agricultural commodity to be used to produce a premium beverage to serve people worldwide. Coffee microbiome turned to be an essential tool to improve the bean quality through the natural fermentation. Therefore, understanding the microbial diversities could create the final product's better quality. This study investigated the natural microbial consortium during the wet process fermentation of coffee onsite in Thailand to characterize the microorganisms involved in correlation toward the biochemical characteristics and metabolic attributes. Roasting is another important step in developing the complex flavor/ aroma that make coffee to be enjoyable. During the roasting process, the beans undergo many complex and alternatively change in the physicochemical properties from the gained substances in the fermentation process. The changing in the formation of the substances responsible for the sensory qualities, physicochemical/ aroma attributes as well as the health benefits of the final product. Using the starter culture could also develop the distinguished characteristics of coffee (Research collaboration with Van Hart company)
คณะวิศวกรรมศาสตร์
This Project has been undertaken to address the need for skill development and knowledge enhancement in pneumatic systems and automation control, which are crucial in today’s manufacturing industry. Pneumatic systems play a vital role in various production processes, including machine control, automated devices, and assembly lines. However, the Department of Measurement and Control Engineering currently lacks a laboratory dedicated to the study and experimentation of pneumatic systems due to the deterioration and lack of maintenance of the previously used equipment. This has resulted in students missing the opportunity to practice essential skills required in the industrial sector. The authors of this thesis recognize the necessity of reviving and developing a pneumatic laboratory that can effectively support teaching, learning, and research activities. This project focuses on studying and developing industrial robotic arm control systems and pneumatic systems, integrating modern technologies such as Programmable Logic Controllers (PLC) and AI Vision. These systems are intended to be applicable to real-world industrial contexts. The outcomes of this project are expected to not only enhance the understanding of relevant technologies but also aim to transform the laboratory into a vital learning hub for current and future students. Furthermore, this initiative seeks to improve the competitiveness of students in the job market and support the development of innovations in the manufacturing industry in the years to come.
คณะวิทยาศาสตร์
With the urgent need for rapid screening of Aflatoxin B1 (AFB1) due to its association with increased liver cirrhosis and hepatocellular carcinoma cases from contaminated agricultural foods, we propose a novel electrochemical aptasensor. This aptasensor is based on trimetallic nanoparticles AuPt-Ru supported by reduced graphene oxide (AuPt-Ru/RGO) modified on a low-cost and disposable goldleaf electrode (GLEAuPt-Ru/RGO) for detection of AFB1. The trimetallic nanoparticle AuPt-Ru was synthesized using an ultrasonic-driven chemical reduction method. The synthesized AuPt-Ru exhibited a waxberry-like appearance, with AuPt core-shell structure and ruthenium dispersed over the particles. The average particle size was 57.35 ± 8.24 nm. The AuPt-Ru was integrated into RGO sheets (inner diameter of 0.5 to 1.6 µm) in order to enhance electron transfer efficiency and increase the specific immobilizing surface area of the thiol-5’-terminated modified aptamer (Apt) to target AFB1. With a large electrochemical surface area and low electrochemical impedance, GLEAuPt-Ru/RGO displays ultra-high sensitivity for AFB1 detection. Differential pulse voltammetry (DPV) measurements revealed a linear range for AFB1 detection range from 0.3 to 30.0 pg mL-1 (R2 = 0.9972), with a limit of detection (LOD, S/N = 3) and a limit of quantification (LOQ, S/N = 10) of 0.009 pg mL-1 and 0.031 pg mL-1, respectively. The developed aptasensor also demonstrated excellent accuracy in real agricultural products, including dried red chili, garlic, peanut, pepper, and Thai jasmine rice, achieving recovery rates between 94.6 and 107.9%. The fabricated aptamer-based GLEAuPt-Ru/RGO performance is comparable to that of a modified commercial electrode, which has great potential application prospects for detecting AFB1 in agricultural products.