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Vélez MA, Wolf VI, Espariz M, Acciarri G, Magni C, Hynes E, Perotti MC. Study of volatile compounds profiles in milk matrices using Enterococcus faecalis EstA and Rhizomucor miehei lipase. Food Res Int 2023; 169:112861. [PMID: 37254435 DOI: 10.1016/j.foodres.2023.112861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 02/02/2023] [Accepted: 04/17/2023] [Indexed: 06/01/2023]
Abstract
The use of esterase/lipase enzymes of different origins in food industry is a widely employed strategy to enhance the formation of characteristic aromatic compounds derived from fat and diversify flavour. In the present work, we studied EstA enzyme of Enterococcus faecalis and a high purity Rhizomucor miehei lipase (Palatase). EstA was obtained recombinantly in Escherichia coli BL21 (DE3), and optimum esterase activity was detected at pH 6.75 and 40 °C. We evaluated the effect of the enzymes on milk mixtures prepared with different fat contents (2.8 and 6%) and structure (native or homogenized) on volatile compounds profiles. The milk fat structure before and after the application of low homogenization was characterized by dynamic light dispersion and microscopy. Native milk fat mixtures presented particles of 4.6 μm and 184 nm and homogenized mixtures had particles of 1.4 μm and 258 nm; microscopy images were in concordance with these results. Fifteen volatile compounds were identified, including ketones, esters, alcohols, and acids. We showed the key role of milk fat levels and microstructure in the nature of the volatile compounds produced by the R. miehei enzyme. Both in native or homogenized states, the highest content of fat favored a higher production of acids whereas the lowest fat level favored a higher esters production along with a more balanced volatile profile. For EstA enzyme, results showed a limited action on fat, as biosynthesis of esters only increased with the highest fat level homogenized.
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Affiliation(s)
- María A Vélez
- Instituto de Lactología Industrial (INLAIN, Universidad Nacional del Litoral/CONICET), Facultad de Ingeniería Química, Santiago del Estero 2829, S3000AOM, Santa Fe, Argentina.
| | - Verónica I Wolf
- Instituto de Lactología Industrial (INLAIN, Universidad Nacional del Litoral/CONICET), Facultad de Ingeniería Química, Santiago del Estero 2829, S3000AOM, Santa Fe, Argentina
| | - Martín Espariz
- Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Suipacha 590, 2000, Rosario, Santa Fe, Argentina
| | - Giuliana Acciarri
- Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Suipacha 590, 2000, Rosario, Santa Fe, Argentina
| | - Christian Magni
- Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Suipacha 590, 2000, Rosario, Santa Fe, Argentina
| | - Erica Hynes
- Instituto de Lactología Industrial (INLAIN, Universidad Nacional del Litoral/CONICET), Facultad de Ingeniería Química, Santiago del Estero 2829, S3000AOM, Santa Fe, Argentina
| | - María C Perotti
- Instituto de Lactología Industrial (INLAIN, Universidad Nacional del Litoral/CONICET), Facultad de Ingeniería Química, Santiago del Estero 2829, S3000AOM, Santa Fe, Argentina
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Zhu M, Xu X, Li Y, Wang P, Niu S, Zhang K, Huang X. Biosynthesis of the Nematode Attractant 2-Heptanone and Its Co-evolution Between the Pathogenic Bacterium Bacillus nematocida and Non-pathogenic Bacterium Bacillus subtilis. Front Microbiol 2019; 10:1489. [PMID: 31312190 PMCID: PMC6614512 DOI: 10.3389/fmicb.2019.01489] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 06/14/2019] [Indexed: 11/13/2022] Open
Abstract
Methylketones are broadly distributed in nature and perform a variety of functions. Most microorganisms are thought to produce methylketone by abortive β-oxidation of fatty acid catalytic metabolism. However, two methylketone synthetase genes in wild tomatoes are reported to synthesize methylketone using intermediates of the fatty acids biosynthetic pathway. In our previous study on Trojan horse-like interactions between the bacterium Bacillus nematocida B16 and its host worm, the chemical 2-heptanone was found to be an important attractant for the hosts. So here we used this model to investigate the genes involved in synthesizing 2-heptanone in microorganisms. We identified a novel methylketone synthase gene yneP in B. nematocida B16 and found enhancement of de novo fatty acid synthesis during 2-heptanone production. Interestingly, a homolog of yneP' existed in the non-pathogenic species Bacillus subtilis 168, a close relative of B. nematocida B16 that was unable to lure worms, but GC-MS assay showed no 2-heptanone production. However, overexpression of yneP' from B. subtilis in both heterologous and homologous systems demonstrated that it was not a pseudogene. The transcriptional analysis between those two genes had few differences under the same conditions. It was further shown that the failure to detect 2-heptanone in B. subtilis 168 was at least partly due to its conversion into 6-methyl-2-heptanone by methylation. Our study revealed methylketone biosynthesis of Bacillus species, and provided a co-evolution paradigm of second metabolites during the interactions between pathogenic/non-pathogenic bacteria and host.
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Affiliation(s)
| | | | | | | | | | | | - Xiaowei Huang
- State Key Laboratory for Conservation and Utilization of Bio-Resources, Key Laboratory for Microbial Resources, Ministry of Education, Yunnan University, Kunming, China
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Fadda S, Leroy-Sétrin S, Talon R. Preliminary characterization of beta-decarboxylase activities in Staphylococcus carnosus 833, a strain used in sausage fermentation. FEMS Microbiol Lett 2004; 228:143-9. [PMID: 14612250 DOI: 10.1016/s0378-1097(03)00749-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
In sausage, Staphylococcus carnosus increases the levels of methyl ketones which could arise from incomplete beta-oxidation of fatty acids followed by a decarboxylation. The objective of this work was to characterize the beta-decarboxylase activities in cell-free extract. By using different substrates, at least two kinds of beta-decarboxylase activities were shown: an acetoacetate-like and an oxaloacetate-like. The first one leads to the production of ketones from ethylbutyryl acetate or acetoacetic acid. The activity was optimal at pH 6.0, stimulated by pyridoxal phosphate but ethylenediamine tetraacetic acid (EDTA), NaCl, iodoacetate and curing additives were inhibitory. The second decarboxylase activity leads to the production of pyruvic acid from oxaloacetic acid. This activity was optimal at pH 5.0 and stimulated by divalent ions and biotin.
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Affiliation(s)
- Silvina Fadda
- INRA Clermont Ferrand--Theix, Station de Recherches sur la Viande, 63122, Saint-Genès Champanelle, France
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Kreit J, Elalami A. Substrate characterization of a NAD-dependent secondary alcohol dehydrogenase from Rhodococcus sp. GK1 (CIP 105335). ACTA ACUST UNITED AC 2002. [DOI: 10.1016/s1381-1177(02)00175-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Fadda S, Lebert A, Leroy-Sétrin S, Talon R. Decarboxylase activity involved in methyl ketone production by Staphylococcus carnosus 833, a strain used in sausage fermentation. FEMS Microbiol Lett 2002; 210:209-14. [PMID: 12044676 DOI: 10.1111/j.1574-6968.2002.tb11182.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Staphylococcus carnosus strain 833, inoculated into sausage, increased the levels of methyl ketones which contributed to the cured aroma. These ketones were predicted to arise from incomplete beta-oxidation followed by a decarboxylation. To check this hypothesis, we measured the beta-decarboxylase activity in resting cells of S. carnosus grown in complex or in synthetic medium, using as substrate a beta-ketoacid, which can be an intermediate of the beta-oxidation pathway. This activity was present throughout the growth period. The enzyme appeared to be constitutive because no induction was observed. High aeration, a pH of 5 and the presence of nitrate promoted the production of methyl ketones.
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Affiliation(s)
- S Fadda
- INRA Clermont Ferrand-Theix, Station de Recherches sur la Viande, 63122 Saint-Genès Champanelle, France
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