Biochemical, microbiological and technological characteristics of type II sourdoughs produced with lactic acid bacteria single-strains / Características bioquímicas, microbiológicas e tecnológicas de sourdoughs tipo II produzidos com uma única cepa de bactéria ácido lática

The interplay between biochemical characteristics and the generation of volatile compounds in 11 type II sourdough fermented by single strains of lactic acid bacteria (LAB) was studied. Samples were collected at 0, 6, 9, 12, 15, 18 and 24h for analyses of microbial growth, pH, titratable acidity and CO2 production. During the first 12h, the LABs entered the stationary phase, and the formation of organic and carboxyl acids, alcohols, and esters were observed. Although acidity is an important characteristic of sourdough, in this work increasing the acetic acid content decreased yeast growth and the CO2 retention capacity of the doughs. The main carbohydrate consumed by autochthonous yeast was influenced by the LAB added (homo-or heterofermentative), as observed by correlation analysis. Maltose and glucose showed a strong and negative correlation with the yeast cell density in the dough fermented by homo and heterofermentative LAB, respectively. Moreover, LAB had an important effect on the aromatic profile, being the alcohols, aldehydes, alkanes, organics acids and esters mainly groups characterized. Altogether, 100 different volatile compounds were identified; however, each dough had a different volatile profile. This study shows, for the first time, the influence of a single strain of LAB on the characteristics of type II sourdough.(AU)

As características bioquímicas e a produção de compostos voláteis em 11 diferentes sourdough tipo II produzido com uma única cepa de bactérias do ácido láctico (BAL) em foi estudada. As amostras foram coletadas às 0, 6, 9, 12, 15, 18 e 24 h para análises de crescimento microbiano, pH, acidez titulável e produção de CO2. Durante as primeiras 12 h, as BAL entraram em fase estacionária, sendo observada a formação de ácidos orgânicos e carboxílicos, álcoois e ésteres. Embora a acidez seja uma característica importante do sourdough, neste trabalho o aumento do teor de ácido acético diminuiu o crescimento das leveduras e a capacidade de retenção de CO2 nas massas. Também foi observado que o principal carboidrato consumido pelas leveduras autóctones foi influenciado pela BAL adicionada (homo ou heterofermentativas), conforme observado pela análise de correlação. A maltose e a glicose apresentaram uma correlação forte e negativa com a densidade celular de levedura na massa fermentada por BAL homo e heterofermentativas, respectivamente. Além disso, a BAL teve efeito importante no perfil aromático, sendo os álcoois, aldeídos, alcanos, ácidos orgânicos e ésteres os principais compostos caracterizados. Ao todo, foram identificados 100 compostos voláteis diferentes; no entanto, cada massa apresentou um perfil volátil diferente. Este estudo mostra, pela primeira vez, a influência de uma única cepa de BAL nas características de sourdough tipo II.(AU)

Effects of Lactobacillus Reuteri E81 Added into Rations of Chukar Partridges (Alectoris Chukar) Fed Under Heat Stress Conditions on Fattening Performance and Meat Quality

This study investigated the effects of the addition of Lactobacillus reuteri E81 (LRE) into rations of chukar partridges (Alectoris chukar) fed under heat stress (HS) conditions on fattening performance and meat quality. This study included 256 chukar partridges aged 1 day. The study comprised an adaptation period of 7 days and a fattening period of 35 days and included 8 different groups with 32 animals in each group. Each group was further divided into four subgroups with eight animals in each subgroup. At the end of the study, the best results in terms of fattening performance in the non-HS groups were obtained in the LRE 600 ppm group and in the HS groups, SLRE 200 ppm had the best effect on average live weight and average live weight increase, whereas SLRE 400 ppm had the best effect on FCR (p 0.05). The analysis of the samples collected from chukar partridges on day 21 showed that, there was no effect on the colour parameters and Thiobarbituric acid reactive substances (TBARS) level in the LRE in the HS and non- HS groups, whereas the meat pH level decreased in the SLRE 400 ppm group (p 0.05). The analysis of the samples collected on day 42 showed that there was no effect on colour parameters in the HS and non-HS groups. TBARS level decreased at the dose of LRE 200 ppm in the non-HS group, and the meat pH level decreased in both HS and non-HS groups (p 0.05).(AU)

Effects of Lactobacillus Reuteri E81 Added into Rations of Chukar Partridges (Alectoris Chukar) Fed Under Heat Stress Conditions on Fattening Performance and Meat Quality

This study investigated the effects of the addition of Lactobacillus reuteri E81 (LRE) into rations of chukar partridges (Alectoris chukar) fed under heat stress (HS) conditions on fattening performance and meat quality. This study included 256 chukar partridges aged 1 day. The study comprised an adaptation period of 7 days and a fattening period of 35 days and included 8 different groups with 32 animals in each group. Each group was further divided into four subgroups with eight animals in each subgroup. At the end of the study, the best results in terms of fattening performance in the non-HS groups were obtained in the LRE 600 ppm group and in the HS groups, SLRE 200 ppm had the best effect on average live weight and average live weight increase, whereas SLRE 400 ppm had the best effect on FCR (p 0.05). The analysis of the samples collected from chukar partridges on day 21 showed that, there was no effect on the colour parameters and Thiobarbituric acid reactive substances (TBARS) level in the LRE in the HS and non- HS groups, whereas the meat pH level decreased in the SLRE 400 ppm group (p 0.05). The analysis of the samples collected on day 42 showed that there was no effect on colour parameters in the HS and non-HS groups. TBARS level decreased at the dose of LRE 200 ppm in the non-HS group, and the meat pH level decreased in both HS and non-HS groups (p 0.05).

Associação de probióticos adicionados à dieta de leitões no aleitamento e na creche: índices zootécnicos e economicidade / Probiotics association added to piglets diets in lactation and nursery: technical and economic evaluation

The aim of this study was to investigate the effects of probiotics association added to piglets diets in lactation and nursery. A total of 144 piglets from birth to 62 days old were raised. The design with two treatments (Control and Probiotic A) was totally randomized in lactation. In the nursery, randomized blocks with factorial arrangement 2x3 were defined: Probiotic A and Probiotic B; Control and Probiotic B; Probiotic A and Probiotic A; Control and Control; Probiotic A with challenged animals; and Control and challenged animals. At 35 days from birth 48 animals of the nursery were orally inoculated with Salmonella Typhimurium. Average weight, feed consumption, average weight gain and feed conversion were assessed. For economic analysis, the costs of diet during the nursery and income of animals sale were calculated. Feed consumption considered for analysis was the one related to the period of 21 to 62 days of life. No effect was observed on evaluated parameters in the maternity. Positive effect was observed on feed conversion for Probiotic A and Probiotic A treatment in nursery. In economic evaluation, Control and Probiotic B treatment showed lower cost compared to other ones, thus representing a satisfactory alternative.(AU)

O experimento foi realizado com o objetivo de investigar efeitos zootécnicos e econômicos da associação de probióticos adicionados à dieta de leitões no aleitamento e na creche. Foram utilizados 144 leitões do nascimento até os 62 dias de idade. No aleitamento o delineamento foi inteiramente casualizado com dois tratamentos: Controle e Probiótico A. Na creche, foram blocos casualizados com arranjo fatorial de tratamentos 2x3: Probiótico A e Probiótico B; Controle e Probiótico B; Probiótico A e Probiótico A; Controle e Controle; Probiótico A e animais desafiados; e Controle e animais desafiados. Aos 35 dias de idade 48 animais da creche foram inoculados com Salmonella Typhimurium via oral. Avaliou-se peso médio, consumo médio de ração, o ganho de peso médio e a conversão alimentar. Para a análise econômica, calcularam-se os custos das dietas durante a creche e o desempenho da receita de comercialização dos animais. O consumo de ração utilizado na análise corresponde àquele ocorrido no período total de 21 a 62 dias de idade. Na maternidade não foi observado efeito nos parâmetros avaliados. Na creche, a conversão alimentar foi favorável ao tratamento Probiótico A Probiótico A. Na avaliação econômica o tratamento Controle Probiótico B apresentou menor custo em relação aos demais, podendo, assim, representar uma alternativa satisfatória.(AU)

Associação de probióticos adicionados à dieta de leitões no aleitamento e na creche: índices zootécnicos e economicidade / Probiotics association added to piglets diets in lactation and nursery: technical and economic evaluation

The aim of this study was to investigate the effects of probiotics association added to piglets diets in lactation and nursery. A total of 144 piglets from birth to 62 days old were raised. The design with two treatments (Control and Probiotic A) was totally randomized in lactation. In the nursery, randomized blocks with factorial arrangement 2x3 were defined: Probiotic A and Probiotic B; Control and Probiotic B; Probiotic A and Probiotic A; Control and Control; Probiotic A with challenged animals; and Control and challenged animals. At 35 days from birth 48 animals of the nursery were orally inoculated with Salmonella Typhimurium. Average weight, feed consumption, average weight gain and feed conversion were assessed. For economic analysis, the costs of diet during the nursery and income of animals sale were calculated. Feed consumption considered for analysis was the one related to the period of 21 to 62 days of life. No effect was observed on evaluated parameters in the maternity. Positive effect was observed on feed conversion for Probiotic A and Probiotic A treatment in nursery. In economic evaluation, Control and Probiotic B treatment showed lower cost compared to other ones, thus representing a satisfactory alternative.

O experimento foi realizado com o objetivo de investigar efeitos zootécnicos e econômicos da associação de probióticos adicionados à dieta de leitões no aleitamento e na creche. Foram utilizados 144 leitões do nascimento até os 62 dias de idade. No aleitamento o delineamento foi inteiramente casualizado com dois tratamentos: Controle e Probiótico A. Na creche, foram blocos casualizados com arranjo fatorial de tratamentos 2x3: Probiótico A e Probiótico B; Controle e Probiótico B; Probiótico A e Probiótico A; Controle e Controle; Probiótico A e animais desafiados; e Controle e animais desafiados. Aos 35 dias de idade 48 animais da creche foram inoculados com Salmonella Typhimurium via oral. Avaliou-se peso médio, consumo médio de ração, o ganho de peso médio e a conversão alimentar. Para a análise econômica, calcularam-se os custos das dietas durante a creche e o desempenho da receita de comercialização dos animais. O consumo de ração utilizado na análise corresponde àquele ocorrido no período total de 21 a 62 dias de idade. Na maternidade não foi observado efeito nos parâmetros avaliados. Na creche, a conversão alimentar foi favorável ao tratamento Probiótico A Probiótico A. Na avaliação econômica o tratamento Controle Probiótico B apresentou menor custo em relação aos demais, podendo, assim, representar uma alternativa satisfatória.

Identification and biological activity of potential probiotic bacterium isolated from the stomach mucus of breast-fed lamb

The lactic acid bacterium E isolated from the stomach mucus of breast-fed lamb was identified by sequencing of 16S rDNA fragment and species-specific PCR as Lactobacillus reuteri. Its potential antimicrobial activity and ability to modulate immune system in vitro and in vivo was determined. The growth inhibition of potential pathogens decreased from Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella enterica ser. Minnesota to Escherichia coli. The lowest inhibition activity was observed in the case of Candida albicans. The ability of L. reuteri E to modulate biological activities of human and mouse mononuclear cells was estimated in vitro and in vivo, respectively. The production of IL-1 by monocytes in vitro was significantly induced by L. reuteri E (relative activity 2.47). The ability to modulate biological activities of mononuclear cells by living L. reuteri E cells in vitro in comparison to disintegrated L. reuteri E cells in vivo differed. For example lysozyme activity in vitro was inhibited while in vivo was stimulated (relative activities 0.30 and 1.83, respectively). The peroxidase activity in vitro was stimulated while in vivo was inhibited (relative activities 1.53 and 0.17, respectively). Obtained results indicate that L. reuteri E is potential candidate to be used in probiotic preparations for animals and/or human.

Identification and biological activity of potential probiotic bacterium isolated from the stomach mucus of breast-fed lamb

The lactic acid bacterium E isolated from the stomach mucus of breast-fed lamb was identified by sequencing of 16S rDNA fragment and species-specific PCR as Lactobacillus reuteri. Its potential antimicrobial activity and ability to modulate immune system in vitro and in vivo was determined. The growth inhibition of potential pathogens decreased from Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella enterica ser. Minnesota to Escherichia coli. The lowest inhibition activity was observed in the case of Candida albicans. The ability of L. reuteri E to modulate biological activities of human and mouse mononuclear cells was estimated in vitro and in vivo, respectively. The production of IL-1 by monocytes in vitro was significantly induced by L. reuteri E (relative activity 2.47). The ability to modulate biological activities of mononuclear cells by living L. reuteri E cells in vitro in comparison to disintegrated L. reuteri E cells in vivo differed. For example lysozyme activity in vitro was inhibited while in vivo was stimulated (relative activities 0.30 and 1.83, respectively). The peroxidase activity in vitro was stimulated while in vivo was inhibited (relative activities 1.53 and 0.17, respectively). Obtained results indicate that L. reuteri E is potential candidate to be used in probiotic preparations for animals and/or human.