Biological Science: Research Developments and Innovations Vol. 2

Lactic Acid Bacteria as Natural Biopreservation Agents in Modern Food Systems: Mechanisms, Antimicrobial Metabolites, and Industrial Applications

Agus Susilo — 2026-09-04

The global shift towards clean-label foods has placed the food industry under increasing pressure to maintain microbiological stability and shelf life without an excessive reliance on synthetic preservatives. Biopreservation using lactic acid bacteria (LAB) offers a scientifically grounded response to this demand. This chapter reviews the role of LAB as producers of natural preservation systems in modern food matrices, integrating literature published between 2008 and 2025. Three conceptual pillars underpin LAB-based biopreservation: ecological competition through nutrient and micronutrient depletion, modification of the food microenvironment via acidification and redox shifts, and the production of inhibitory metabolites. The metabolite spectrum discussed includes organic acids, hydrogen peroxide, carbon dioxide, diacetyl, bacteriocins, phenyllactic acid (PLA), and the reuterin system, each examined in terms of its mechanism of action, target microorganisms, and applicable food matrices. Bacteriocins are considered in detail as ribosomally synthesised antimicrobial peptides that act through pore formation and lipid II binding, with nisin remaining the principal example approved for wide regulatory use. Antifungal applications, particularly phenyllactic acid and sourdough-based systems capable of delaying mould growth in bread for approximately ten days, are also addressed, together with the reuterin system, which can be generated in situ from food-grade glycerol and exhibits broad-spectrum activity. Evidence from processed meat, dairy, bakery, and chilled ready-to-eat products indicates that protective cultures are currently the most industrially practical format, since antimicrobial metabolites are produced in situ and microorganisms with recognised safety status face comparatively straightforward regulatory pathways. The principal challenge is no longer demonstrating efficacy but standardising performance across matrices, preserving sensory quality, managing the risk of microbial adaptation and microbiome shifts, and satisfying regulatory and labelling requirements. Integration of omics-based strain selection, quantitative predictive modelling, encapsulation, and edible coating technologies within a multiple-hurdle framework is identified as the most promising direction for accelerating responsible industrial adoption.

Gastroprotective Efficacy of Thespesia garckeana Fruit Pericarp: Insights from Phytochemistry and Toxicology

Ogundeko Timothy Olugbenga — 2026-09-04

Peptic ulcer disease remains an important gastrointestinal disorder, while non-steroidal anti-inflammatory drug exposure, alcohol-related mucosal injury, recurrence, adverse effects and treatment access continue to justify the search for safe and affordable gastroprotective agents. Thespesia garckeana (syn. Azanza garckeana in some literature), popularly known as Goron Tula, is an ethnomedicinal plant with reported gastrointestinal and other therapeutic applications. This chapter integrates experimental evidence on the fruit pericarp, combining preliminary phytochemical screening, acute oral toxicity assessment, and anti-ulcer studies in aspirin- and ethanol-induced gastric injury models. Solvent extraction yield was aqueous (36.95%), ethanolic (39.09%) and methanolic (44.02%) with array of secondary metabolite classes (phytochemical profile). No mortality occurred up to 5,000 mg/kg in the oral acute toxicity study, although mild transient behavioral changes were observed. In male rats, methanolic extract (METG) at 200 mg/kg produced 99.4% inhibition in the aspirin model and 66.5% in the ethanol model, with the aspirin response closely approaching rabeprazole (98.8%). In female rats, the corresponding inhibition values were 79.6% and 69.0%. A restricted block analysis using sex as the blocking factor demonstrated significant variation attributable to sex (F=23.00, p<0.001) and a highly significant treatment effect (F=686.86, p<0.0001). These findings support a multifactorial gastroprotective profile involving antioxidant, anti-inflammatory, mucosal-defensive and cytoprotective actions, while the non-linear dose response indicates that higher dose does not necessarily confer greater protection, thus the crude methanol plant extract of T. garckeana demonstrated maximum anti-ulcer efficacy at a mid-range dose (200 mg/kg) but loses efficacy at a higher dose (400 mg/kg) exhibiting a classic biphasic dose-response relationship. The evidence supports further phytochemical standardization, mechanistic studies, toxicological evaluation, formulation research and eventual clinical investigation, rather than immediate clinical substitution for established anti-ulcer therapy.

Population Trends of Peccaries and Deer, Hunting, and Socioeconomic Factors in Rural Communities of Southern Yucatan, Mexico

Rubén C. Montes-Pérez — 2026-09-04

The objective of this chapter is to analyse estimates of the population density of collared peccary (Pecari tajacu), white-tailed deer (Odocoileus virginianus), and temazate deer (Mazama americana) during 2003–2004, 2007–2008, and 2008–2009 in the municipality of Tzucacab, Yucatán, in relation to hunting pressure on these populations and socioeconomic factors in rural communities. Seven 5-km linear transects were randomly established in the municipality in 2003–2004, and 18 were established between 2007 and 2009. Population estimates were obtained through direct sightings, track counts, and counts of deer pellets in plots located along the same transects. The results showed that population densities differed according to the method used. However, densities decreased significantly when the peccary track-count method was used from 2003–2004 to 2008–2009, with 95% confidence intervals (95% CI) of [1.7, 0.08] animals/km², respectively. Deer population densities also decreased from 2003–2004 to 2007–2009, with 95% CI values of [7.194, 0.217] deer/km², respectively, using the plot-based deer-pellet count method. The working hypothesis is that hunting intensity makes these populations vulnerable, based on reports from these periods. The study also discusses socioeconomic and political factors, including poverty, low educational attainment, chronic diseases, and a shortage of formal, permanent employment among the rural population, as conditions underlying the patterns described in this paper.