{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,23]],"date-time":"2026-07-23T05:35:24Z","timestamp":1784784924903,"version":"3.55.0"},"reference-count":39,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2022,1,25]],"date-time":"2022-01-25T00:00:00Z","timestamp":1643068800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100003725","name":"National Research Foundation of Korea","doi-asserted-by":"publisher","award":["NRF-2020R1A2C2004724"],"award-info":[{"award-number":["NRF-2020R1A2C2004724"]}],"id":[{"id":"10.13039\/501100003725","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Korea government (BK 21 FOUR)","award":["No. 4299990914600"],"award-info":[{"award-number":["No. 4299990914600"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Metabolites"],"abstract":"<jats:p>Bacillus subtilis is often exposed to diverse culture conditions with the aim of improving hygiene or food quality. This can lead to changes in the volatile metabolite profiles related to the quality of fermented foods. To comprehensively interpret the associated metabolic expressions, changes in intracellular primary and extracellular secondary volatile metabolites were investigated by exposing B. subtilis to an alkaline pH (BP, pH 8.0) and a high salt concentration (BS, 1 M). In particular, B. subtilis was cultured in a leucine-enriched medium to investigate the formation of leucine-derived volatile metabolites. This study observed metabolic changes in several metabolic pathways, including carbohydrate metabolism, amino acid metabolism, fatty acid metabolism, and leucine degradation. The formation of proline (an osmolyte), furans, pyrrole, and monosaccharide sugars (glucose, galactose, and fructose) was enhanced in BS, whereas fatty acid derivatives (ketones and alcohols) increased in BP. In the case of leucine degradation, 3-methyl-butanal and 3-methylbutanol could be salt-specific metabolites, while the contents of 3-methylbutanoic acid and 3-methylbutylacetate increased in BP. These results show culture condition-specific metabolic changes, especially secondary volatile metabolites related to the sensory property of foods, in B. subtilis.<\/jats:p>","DOI":"10.3390\/metabo12020112","type":"journal-article","created":{"date-parts":[[2022,1,25]],"date-time":"2022-01-25T20:40:18Z","timestamp":1643143218000},"page":"112","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":15,"title":["Effects of pH and Osmotic Changes on the Metabolic Expressions of Bacillus subtilis Strain 168 in Metabolite Pathways including Leucine Metabolism"],"prefix":"10.3390","volume":"12","author":[{"given":"Min-Kyung","family":"Park","sequence":"first","affiliation":[{"name":"Department of Food Science and Biotechnology, Ewha Womans University, Seoul 03760, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Soyeon","family":"Lee","sequence":"additional","affiliation":[{"name":"Department of Food Science and Biotechnology, Ewha Womans University, Seoul 03760, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1343-5647","authenticated-orcid":false,"given":"Young-Suk","family":"Kim","sequence":"additional","affiliation":[{"name":"Department of Food Science and Biotechnology, Ewha Womans University, Seoul 03760, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,1,25]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"5","DOI":"10.1016\/S1389-0344(02)00003-5","article-title":"Metabolomics: Quantification of intracellular metabolite dynamics","volume":"19","author":"Buchholz","year":"2002","journal-title":"Biomol. Eng."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"881","DOI":"10.1007\/s10068-021-00917-9","article-title":"Mass spectrometry based metabolomics approach on the elucidation of volatile metabolites formation in fermented foods: A mini review","volume":"30","author":"Park","year":"2021","journal-title":"Food Sci. Biotechnol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"845","DOI":"10.1111\/j.1365-2958.2005.04587.x","article-title":"Bacillus subtilis antibiotics: Structures, syntheses and specific functions","volume":"56","author":"Stein","year":"2005","journal-title":"Mol. Microbiol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"189","DOI":"10.1016\/S0168-1605(01)00706-1","article-title":"Flavouring composition prepared by fermentation with Bacillus spp.","volume":"75","author":"Beaumont","year":"2002","journal-title":"Int. J. Food Microbiol."},{"key":"ref_5","first-page":"572","article-title":"Characteristics of taste components of chongkukjang fermented with Bacillus subtilis","volume":"13","author":"Lee","year":"2004","journal-title":"Food Sci. Biotechnol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"175","DOI":"10.1016\/j.foodres.2018.06.033","article-title":"Correlation between the key aroma compounds and gDNA copies of Bacillus during fermentation and maturation of natto","volume":"112","author":"Liu","year":"2018","journal-title":"Food Res. Int."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"870","DOI":"10.1128\/JB.01106-09","article-title":"A comprehensive proteomics and transcriptomics analysis of Bacillus subtilis salt stress adaptation","volume":"192","author":"Hahne","year":"2010","journal-title":"J. Bacteriol."},{"key":"ref_8","first-page":"776","article-title":"Production dynamics of extracellular protease from Bacillus species","volume":"4","author":"Olajuyigbe","year":"2005","journal-title":"Afr. J. Biotechnol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1898","DOI":"10.1111\/1462-2920.12438","article-title":"Adaptation of Bacillus subtilis carbon core metabolism to simultaneous nutrient limitation and osmotic challenge: A multi-omics perspective","volume":"16","author":"Kohlstedt","year":"2014","journal-title":"Environ. Microbiol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"115","DOI":"10.1016\/j.jgeb.2017.02.001","article-title":"Microbial alkaline proteases: Optimization of production parameters and their properties","volume":"15","author":"Sharma","year":"2017","journal-title":"J. Genet. Eng. Biotechnol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"8120","DOI":"10.1021\/jf0303159","article-title":"Volatile organic compounds in foods: A five year study","volume":"51","author":"Smith","year":"2003","journal-title":"J. Agric. Food Chem."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"261S","DOI":"10.1093\/jn\/133.1.261S","article-title":"The role of leucine in weight loss diets and glucose homeostasis","volume":"133","author":"Layman","year":"2003","journal-title":"J. Nutr."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1519","DOI":"10.1172\/JCI1326","article-title":"Bidirectional modulation of insulin action by amino acids","volume":"101","author":"Patti","year":"1998","journal-title":"J. Clin. Invest."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1111\/1751-7915.13043","article-title":"Bacillus subtilis, the model gram-positive bacterium: 20 years of annotation refinement","volume":"11","author":"Borris","year":"2017","journal-title":"Microb. Biotechnol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"2812","DOI":"10.1039\/C3AY41907J","article-title":"Principal component analysis","volume":"6","author":"Bro","year":"2014","journal-title":"Anal. Methods"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1039\/C4MB00414K","article-title":"PLS\/OPLS models in metabolomics: The impact of permutation of dataset rows on the K-fold cross-validation quality parameters","volume":"11","author":"Triba","year":"2015","journal-title":"Mol. Biosyst."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"14127","DOI":"10.1038\/s41598-018-32447-6","article-title":"Metabolite accumulation and metabolic network in developing roots of Rehmannia glutinosa reveals its root developmental mechanism and quality","volume":"8","author":"Zhou","year":"2018","journal-title":"Sci. Rep."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1323","DOI":"10.1002\/jctb.722","article-title":"Bioflavours and fragrances via fermentation and biocatalysis","volume":"77","author":"Vandamme","year":"2002","journal-title":"J. Chem. Technol. Biotechnol."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"5335","DOI":"10.1128\/JB.05490-11","article-title":"Osmotically controlled synthesis of the compatible solute proline is critical for cellular defense of Bacillus subtilis against high osmolarity","volume":"193","author":"Brill","year":"2011","journal-title":"J. Bacteriol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"747","DOI":"10.1104\/pp.122.3.747","article-title":"Genetic engineering of glycinebetaine production toward enhancing stress tolerance in plants: Metabolic limitations","volume":"122","author":"Huang","year":"2000","journal-title":"Plant Physiol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"15898","DOI":"10.1073\/pnas.252637799","article-title":"Trehalose accumulation in rice plants confers high tolerance levels to different abiotic stresses","volume":"99","author":"Garg","year":"2002","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"396","DOI":"10.5483\/BMBRep.2007.40.3.396","article-title":"Expression of Bacillus subtilis proBA genes and reduction of feedback inhibition of proline synthesis increases proline production and confers osmotolerance in transgenic arabidopsis","volume":"40","author":"Chen","year":"2007","journal-title":"BMB Rep."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Ferreira, I.M., and Guido, L.F. (2018). Impact of wort amino acids on beer flavour: A review. Fermentation, 4.","DOI":"10.3390\/fermentation4020023"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"C368","DOI":"10.1111\/j.1750-3841.2011.02068.x","article-title":"Comparison of fermented soybean paste (Doenjang) prepared by different methods based on profiling of volatile compounds","volume":"76","author":"Jo","year":"2011","journal-title":"J. Food Sci."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"78","DOI":"10.3389\/fbioe.2014.00078","article-title":"Production of fatty acid-derived valuable chemicals in synthetic microbes","volume":"2","author":"Yu","year":"2014","journal-title":"Front. Bioeng. Biotechnol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"610936","DOI":"10.3389\/fbioe.2020.610936","article-title":"Biosynthesis of fatty alcohols in engineered microbial cell factories: Advances and limitations","volume":"8","author":"Krishnan","year":"2020","journal-title":"Front. Bioeng. Biotechnol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"777","DOI":"10.1039\/C7GC03046K","article-title":"Biocatalysis of carboxylic acid reductases: Phylogenesis, catalytic mechanism and potential applications","volume":"20","author":"Qu","year":"2018","journal-title":"Green Chem."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"441","DOI":"10.1111\/jfq.12060","article-title":"Optimization of isoamyl acetate production in a solvent-free system","volume":"36","author":"Azudin","year":"2013","journal-title":"J. Food Qual."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Liu, M., Bienfait, B., Sacher, O., Gasteiger, J., Siezen, R.J., Nauta, A., and Geurts, J.M.W. (2014). Combining chemoinformatics with bioinformatics: In silico prediction of bacterial flavor forming pathways by a chemical systems biology approach \u201creverse pathway engineering\u201d. PLoS ONE, 9.","DOI":"10.1371\/journal.pone.0084769"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"32081","DOI":"10.1038\/srep32081","article-title":"Characterization of a novel low-temperature-active, alkaline and sucrose-tolerant invertase","volume":"6","author":"Zhou","year":"2016","journal-title":"Sci. Rep."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"5266","DOI":"10.1039\/c1cs15131b","article-title":"Transformations of biomass derived platform molecules: From high added-value chemicals to fuels via aqueous-phase processing","volume":"40","author":"Luque","year":"2011","journal-title":"Chem. Soc. Rev."},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Sadh, P.K., Kumar, S., Chawla, P., and Duhan, J.S. (2018). Fermentation: A boon for production of bioactive compounds by processing of food industries wastes (by-products). Molecules, 23.","DOI":"10.3390\/molecules23102560"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"510","DOI":"10.1128\/JB.01505-12","article-title":"Osmotic control of opuA expression in Bacillus subtilis and its modulation in response to intracellular glycine betaine and proline pools","volume":"195","author":"Hoffmann","year":"2013","journal-title":"J. Bacteriol."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"115","DOI":"10.1016\/j.exppara.2011.07.006","article-title":"Enzymes of the ornithine\u2013glutamate\u2013 proline pathway in the sheep abomasal nematode parasites Haemonchus contortus and Teladorsagia circumcincta","volume":"129","author":"Umair","year":"2011","journal-title":"Exp. Parasitol."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"529","DOI":"10.5010\/JPB.2010.37.4.529","article-title":"Exogenous proline mitigates the detrimental effects of saline and alkaline stresses in Leymus chinensis (Trin.)","volume":"37","author":"Sun","year":"2010","journal-title":"J. Plant Biotechnol."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"443","DOI":"10.1271\/bbb.90814","article-title":"The pathway of leucine to mevalonate in halophilic Archaea: Efficient incorporation of leucine into isoprenoidal lipid with the involvement of isovaleryl-CoA dehydrogenase in Halobacterium salinarum","volume":"74","author":"Yamauchi","year":"2010","journal-title":"Biosci. Biotechnol. Biochem."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"454","DOI":"10.1016\/j.foodres.2008.12.005","article-title":"Enzymatic synthesis of banana flavour (isoamyl acetate) by Bacillus licheniformis S-86 esterase","volume":"42","author":"Torres","year":"2009","journal-title":"Food Res. Int."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"108986","DOI":"10.1016\/j.foodres.2020.108986","article-title":"Characterization of perceptual interactions among ester aroma compounds found in Chinese Moutai Baijiu by gas chromatography-olfactometry, odor Intensity, olfactory threshold and odor activity value","volume":"131","author":"Niu","year":"2020","journal-title":"Food Res. Int."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"108270","DOI":"10.1016\/j.ijfoodmicro.2019.108270","article-title":"Comparative study on metabolic changes of Aspergillus oryzae isolated from fermented foods according to culture conditions","volume":"307","author":"Park","year":"2019","journal-title":"Int. J. Food Microbiol."}],"container-title":["Metabolites"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2218-1989\/12\/2\/112\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T22:07:25Z","timestamp":1760134045000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2218-1989\/12\/2\/112"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,1,25]]},"references-count":39,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2022,2]]}},"alternative-id":["metabo12020112"],"URL":"https:\/\/doi.org\/10.3390\/metabo12020112","relation":{},"ISSN":["2218-1989"],"issn-type":[{"value":"2218-1989","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,1,25]]}}}