KMITL Expo 2026 LogoKMITL 66th Anniversary Logo

Genomic analysis, Bacteriocin dynamic production of putatively novel bacteriocin DCR3-2 inhibiting Listeria monocytogenes synthesized by Lactococcus lactis subsp. hordinae DCR3-2 isolated from Thai pickled crab (Pu-dong)

Abstract

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.

Objective

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

Other Innovations

Developing An Open-Source Tool for Power System and Microgrid Analysis

คณะวิศวกรรมศาสตร์

Developing An Open-Source Tool for Power System and Microgrid Analysis

In this project, we introduce Power Grid Analyzer (PGAz), an open-source software package based on MATLAB, specifically designed for analyzing and controlling future power grids. Initially, PGAz is equipped with four fundamental features: power flow (PF), optimal power flow (OPF), small-signal stability analysis (SSSA), and time-domain simulation (TS). At this stage, Part I concentrates on the development of PF and OPF. The formats of our developed tool are presented, along with its command prompts. In this part, we have developed several conventional yet effective methods in the PGAz package to address PF and OPF problems, including techniques such as the Newton-Raphson method, Gauss-Seidel method, Interior Point Method, Iwamoto’s method, Fast Decoupled Load Flow, Genetic Algorithm, and Particle Swarm Optimization. Additionally, it emphasizes important aspects, algorithms, and various case studies that have been tested against IEEE benchmarks ranging from the IEEE 5-bus to the IEEE 300-bus test systems. The results demonstrate the capabilities of PGAz for future educational and research applications in PF and OPF. Finally, we outline a plan for developing Part II, which will mainly focus on SSSA and TS.

Read more
Production of Lactic acid bacteria prototype from Thailand for use as probiotics for livestock animals

คณะเทคโนโลยีการเกษตร

Production of Lactic acid bacteria prototype from Thailand for use as probiotics for livestock animals

This research gives a comprehensive overview of the use of antibiotics in livestock production, highlighting both the benefits and the risks associated with their use. The benefits, such as improving immunity, digestion, and reducing infections, are contrasted with the growing concern over antibiotic residues and the development of drug resistance. The shift towards alternatives like probiotics is explored as a sustainable solution, with a specific focus on lactic acid bacteria (LAB) found in the digestive systems of livestock. Thailand’s regulations, which control antibiotic use in animal feed, are also discussed, setting the stage for the study on LAB as a potential replacement for imported probiotics. 1. Use of Antibiotics in Livestock: Antibiotics have been used to promote growth, improve digestion, and prevent infections in livestock. However, the improper use of antibiotics can lead to residues in animal products and the development of drug-resistant bacteria. 2. Global Trends in Antibiotic Use: Many countries, like the European Union and Japan, have banned antibiotics as growth promoters, while others, like China and the U.S., are planning similar bans. 3. Thailand's Approach: Thailand has implemented a regulation since September 2020 to control the use of antibiotics in animal feed, requiring control at both feed mills and farms that mix their own feed. 4. Probiotics as an Alternative: Probiotics, particularly lactic acid bacteria (LAB), are being studied as an alternative to antibiotics. LAB are naturally found in the digestive tracts of livestock and are considered beneficial for maintaining gut health and replacing the need for antibiotics. The study examines the potential of LAB from Thai livestock (broilers, pigs, and cattle) as a sustainable alternative to imported probiotics, aiming to overcome issues like low survival rates of foreign probiotics in practice.

Read more
Ginbanirose

คณะอุตสาหกรรมอาหาร

Ginbanirose

The Ginbanirose project aims to develop herbal extracts for alleviating menstrual pain using key ingredients: roselle, banana inflorescence, and ginger. These ingredients contain bioactive compounds with anti-inflammatory, antioxidant, and pain-relieving properties. The extracts are enhanced through liposome encapsulation technology, which improves absorption and stability. The production process involves herbal extraction, freeze-drying, and liposome formulation using lecithin and stabilizers. Experimental results demonstrate high phenolic content and antioxidant activity via the DPPH method. Ginbanirose addresses women’s quality of life concerns while offering significant business opportunities in the rapidly growing herbal market, particularly in the Asia-Pacific region.

Read more