Abstract: In recent years, health consciousness has increased more and more in Japan, and lactic acid bacteria beverages, lactic acid fermented foods and related supplements have become popular. As for European cheese and yogurt, many products are sold in Japan. On the other hand, information on lactic acid bacteria beverages and fermented lactic acid foods in Mongolia and Central Asia is limited, and it can be said that we never eat dairy products or dairy products from those countries. In this article, we have explained in detail about the lesser-known Mongolian dairy products and dairy products.
This commentary article was created based on a request from the editorial department of the Brewing Society of Japan. The details of this research are published as a comprehensive treatise in the academic report of the Faculty of Agriculture, Okayama University.
KEY WORDS: airag, bacteriocin, lactic acid bacteria, Leuconostoc mesenteroides, listericidal activity
Abstract: Strain 213M0 was selected with productivity of a bacteriocin-like inhibitory substance (BLIS) among 235 strains of lactic acid bacteria (LAB) isolated from Mongolian fermented milk ‘airag’. Strain 213M0 was species-identified as [I]Leuconostoc mesenteroides[I] subsp. [I]dextranicum[I] by morphological observation, carbohydrate fermentation profiling and sequencing the 16S rRNA gene. Incubation temperature proper to produce the BLIS was 25°C rather than 30 and 37°C, and the production actively proceeded during the exponential growth phase of the producer cells. Antibacterial effect of BLIS 213M0 was limited to all nine strains of [I]Listeria[I] sp. bacteria and seven strains of LAB cocci among 53 tested strains, which corresponds to a typical feature of the class IIa pediocin-like bacteriocins. BLIS 213M0 was not inactivated in every broad pH range solution (pH 2.0-11.0), and was stable against storage at 25°C for 1 week and heating at 121°C for 15 min under pH 4.5. Peptide frame of BLIS 213M0 was confirmed by inactivation with some peptidases, and then its molecular weight was estimated to be 2.6-3.0 kDa using an [I]in situ[I] activity assay following sodium dodecyl sulfate polyacrylamide gel electrophoresis. The estimated size was different from the other [I]Leuconostoc[I] bacteriocins already reported. These results suggest that BLIS 213M0 would be a novel listericidal bacteriocin.
Abstract: [I]Leuconostoc mesenteroides[I] 406 was isolated from the traditional fermented mare milk airag in Tuv Aimag, Mongolia. This strain produces an antilisterial bacteriocin. Here, we report the draft genome sequence of this organism.
Abstract: [I]Leuconostoc mesenteroides[I] 213M0 was isolated from traditional fermented mare milk airag in Bulgan Aimag, Mongolia. This strain produces a listericidal bacteriocin-like inhibitory substance. Here, we report the draft genome sequence of this organism.
KEY WORDS: airag, alcoholic fermented milk, lactic acid bacteria, yeasts, traditional preparation process
Abstract: Airag, a traditional fermented milk well loved by Mongolians, has been drunk habitually since
ancient times as a unique drink. It is produced from cow, mare and camel milk by a traditional method using indigenous starter cultures containing lactic acid bacteria, yeasts and other fermentative microorganisms. Spontaneously fermented milk products have for centuries been consumed for their therapeutic value in promoting health and well-being, especially among the pastoral communities in Mongolia. Most traditional fermentations are conducted as uncontrolled processes, however, increasing research, such as that focused on compositional properties and microbial biota properties, offers prospective views for improving spontaneous fermented products with respect to safety, shelf life, sensory characteristics, and nutritional and functional qualities. The aim of this article is to investigate progress in the microbiological research on the traditional alcoholic fermented milk, airag, in Mongolia and to give an outline of the traditional preparation processes.
KEY WORDS: airag, Lactobacillus helveticus, cell envelope proteinase, cleavage cite specificity
Abstract: Airag is a traditional fermented milk of Mongolia that is usually made from raw mare's milk. [I]Lactobacillus helveticus[I] is one of the lactic acid bacteria most frequently isolated from airag. In this study, we investigated the genetic and physiological characteristics of [I]L. helveticus[I] strains isolated from airag and clarified their significance in airag by comparing them with strains from different sources. Six strains of [I]L. helveticus[I] were isolated from five home-made airag samples collected from different regions of Mongolia. The optimal temperature for acidification in skim milk was 30 to 35 °C for all the Mongolian strains, which is lower than those for the reference strains (JCM 1554 and JCM 1120T) isolated from European cheeses. All of the strains had a prtH1-like gene encoding a variant type of cell envelope proteinase (CEP). The CEP amino acid sequence in Snow Brand Typeculture (SBT) 11087 isolated from airag shared 71% identity with PrtH of [I]L. helveticus[I] CNRZ32 (AAD50643.1) but 98% identity with PrtH of [I]Lactobacillus kefiranofaciens[I] ZW3 (AEG40278.1) isolated from a traditional fermented milk in Tibet. The proteolytic activities of the CEP from SBT11087 on artificial substrate (N-succinyl-Ala-Ala-Pro-Phe-p-nitroanilide) and pure casein were measured using an intact-cell degradation assay. The activity of the CEP from SBT11087 was observed to be weak and exhibited a lower optimal temperature (40 °C) than those from the reference strains (45–50 °C). The specificity of the SBT11087 CEP for αS1-casein was typical of the CEPs previously reported in [I]L. helveticus[I], as determined through the degradation profiles obtained through gel electrophoresis and mass spectrometry analyses. In contrast, the degradation profile of β-casein revealed that the CEP of SBT11087 primarily hydrolyzes its C-terminal domain and hydrolyzed nine of the 16 cleavage sites shared among the CEPs of other [I]L. helveticus[I] strains. Thus, the CEP of SBT11087 is distinct from those from previously reported [I]L. helveticus[I] strains in terms of its optimal temperature and its degradation of β-casein. Therefore, the Mongolian [I]L. helveticus[I] strains differ from other strains of the species in different collections and are specifically suited for the natural lactic acid bacterial population in airag.
KEY WORDS: Drought Vulnerability Sensitivity Resilience Steppe NDVI
Abstract: The present study aims to identify hotspots on
the Asian steppe that were vulnerable to widespread
drought events in the Northern Hemisphere during
1999–2002, using newly proposed indices of vegetation
response (sensitivity and resilience) to drought. Drought
sensitivity is defined as vegetation response to decreased
precipitation from pre-drought to drought phases, and
resilience is defined as response to increased precipitation
from drought to post-drought phases. Thus, the sensitivity
and resiliency indices SI and RI are similarly expressed as
normalized change of vegetation relative to that of precipitation. We also develop new regionally adjusted indices
SIr and RIr, to do an interregional comparison of vegetation
dynamics. In general, the resilience (RIr or RI) was larger
than sensitivity (SIr or SI) over the entire region, whereas
they had similar amplitudes over a wetter region (forest
steppe). This asymmetric response of SIrRIr, which
manifested over the desert steppe/steppe regions, is explained by interannual change of plant species composition (i.e., larger ratio of annual/perennial species for the
post-drought year of 2003). As for the steppe region, the
Chinese section had much higher resilience during the
post-drought year compared with the Mongolian one. This
may be attributable to the larger annual/perennial ratio, but
is not strongly related to grazing pressure. Spatial and
temporal analyses of the indices identified locations where
there was not resilience from drought-affected vegetation
conditions despite increased precipitation, and/or where
long-term stability of vegetation is under threat.