Plants show varied cellular responses to salinity that are partly associated with maintaining low cytosolic Na⁺ levels and a high K⁺/Na⁺ ratio. Plant metabolites change with elevated Na⁺, some changes are likely to help restore osmotic balance while others protect Na⁺-sensitive proteins. Metabolic responses to salt stress are described for two barley (Hordeum vulgare L.) cultivars, Sahara and Clipper, which differed in salinity tolerance under the experimental conditions used. After 3 weeks of salt treatment, Clipper ceased growing whereas Sahara resumed growth similar to the control plants. Compared with Clipper, Sahara had significantly higher leaf Na⁺ levels and less leaf necrosis, suggesting they are more tolerant to accumulated Na⁺. Metabolite changes in response to the salt treatment also differed between the two cultivars. Clipper plants had elevated levels of amino acids, including proline and GABA, and the polyamine putrescine, consistent with earlier suggestions that such accumulation may be correlated with slower growth and/or leaf necrosis rather than being an adaptive response to salinity. It is suggested that these metabolites may be an indicator of general cellular damage in plants. By contrast, in the more tolerant Sahara plants, the levels of the hexose phosphates, TCA cycle intermediates, and metabolites involved in cellular protection increased in response to salt. These solutes remain unchanged in the more sensitive Clipper plants. It is proposed that these responses in the more tolerant Sahara are involved in cellular protection in the leaves and are involved in the tolerance of Sahara leaves to high Na⁺.

Purpose: Diabetes is a chronic metabolic disease that accounted for 6 per cent of total Indonesian deaths in 2016. The purpose of this study is to evaluate the ability of milk fermented using intestinal origin Lactobacillus casei strains to alleviate hyperglycemia in rats. Design/methodology/approach: L. casei strains AP and AG were previously isolated and identified from feces of breastfed Indonesian infants (<1 month-old) and confirmed to be probiotics in vitro. These strains were used as bacterial starters to ferment milk, and the fermented product was fed to 25 diabetic rats for 15 days; metformin was used as a positive control. Blood glucose concentration, lipid profiles and total lactic acid bacteria counts were analyzed before and after treatment. Findings: The results showed that feeding rats with milk fermented using L. casei strain AP decreased blood glucose concentration from 172.4 ± 2.1 to 147.2 ± 6.0 mg/dL (p < 0.05), whereas metformin reduced blood glucose concentration from 173.5 ± 6.5 to 124.2 ± 16.9 mg/dL (p < 0.05). Feeding milk fermented either L. casei AP or AG decreased low density lipoprotein but increased high density lipoprotein levels (p < 0.05). Research limitations/implications: This research finding is expected to increase the development of fermented dairy products as functional food, solutions for the prevention of hyperglycemia diseases which have a higher risk to occur on humans. Practical implications: Further study is needed to examine the effect of L. casei AP-fermented milk on humans with hyperglycemia. Social implications: This research finding is expected to increase the development of fermented dairy products as functional food. Originality/value: Oral administration of L. casei AP-fermented milk reduced hyperglycemia in rats similar to metformin. Further study is needed to examine the effect of L. casei AP-fermented milk on humans with hyperglycemia.

Food Science of Animal Resources (Food Sci. Anim. Resour.) is an international, peer-reviewed bimonthly journal publishing original research and reviews on basic and applied aspects of the use of animal resources including the meat, egg, dairy, and edible insect/worm products. Food Sci. Anim. Resour. is published and distributed by the Korean Society for Food Science of Animal Resources.

This study evaluated the ability of two strains of bacterial starter cultures, Lactobacillus casei AP (AP) and Lactobacillus casei AG (AG), to produce exopolysaccharides (EPSs). First, the physicochemical properties of the fermented milk produced by AP and AG were assessed, including physical qualities like viscosity and syneresis and chemical qualities, such as pH, acidity, protein, lactose, fat content, and total solid. Then, AP and AG's ability to produce EPS was measured. Additionally, the EPS' microstructure was observed using a scanning electron microscope, and its chemical structure was assessed using Fourier transform-infrared (FT-IR) spectroscopy. Also, AP and AG's ability to produce EPS was tracked at the molecular level by studying the glycosyltransferase (gtf) gene. Statistical analysis showed that the milk fermented using AP and AG had similar physicochemical qualities (P > 0.05) but significantly different physical qualities (P < 0.05). Additionally, the milk fermented with AP had lower viscosity (1137.33 ± 34.31 centiPoise) than AG (1221.50 ± 20.66 centiPoise). In addition, the milk fermented using AP had higher syneresis (19.42%) than AG (17.83%). The higher viscosity and lower syneresis in the milk fermented using AG were associated with AG's ability to produce more EPS (1409 mg/L) than AP (1204 mg/L). In addition, according to the FT-IR analysis, the AP- and AG-synthesized EPS contained absorption bands at 3323, 2980, 2901, 1642, 1084, 1043, and 873 cm⁻¹. The absorption band at 1642 and 2980 cm⁻¹ corresponds to carbonyl and methylene groups, respectively. Absorption band 873 cm⁻¹ is characteristic of the α-glycosidic bond of α-glucan in EPS. Moreover, the absorption bands on the wavelength region corresponding to the functional groups in the AP- and AG-produced EPS were similar to those in commercially available EPS. Lastly, gtf, contributing to EPS synthesis, was found in the genomes of AP and AG, suggesting the role of glycosyltransferase in the EPS synthesis by both strains.

Kefir is traditionally produced by fermenting cow’s milk using kefir grains as a starter culture. As the viability of microbes within kefir grains is limited and preparing the grains for kefir fermentation is laborious, here, a single starter that ferments lactose and produces ethanol is developed. For this purpose, it is important to isolate yeasts that can ferment lactose and subsequently produce alcohol. This study aimed to isolate and identify yeasts from kefir and characterise their ability as single starters to produce kefir. Based on morphological and physiological evaluations, 15 presumptive yeast isolates were obtained, 10 of which grew well on lactose-containing media. Those that were able to grow on lactose using only carbon sources were subjected to molecular identification based on the internal transcribed spacer (ITS) of the 5.8 rDNA using PCR technology. Molecular identification confirmed four isolates—namely, KFA 3, KFA 7, KFA 9 and KFB 1—as belonging to Kluyveromyces marxianus. The batch fermentation data of these strains were fitted on a logistic model to obtain the carrying capacity coefficients and strain performances were compared. The kinetic modelling revealed that KFA 9 had the highest values for the carrying capacity coefficient, biomass yield and product yield, indicating that, among the four K. marxianus strains, this was superior due to its relatively fast growth and good ethanol productivity.