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1.
Bioresour Technol ; 291: 121872, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31377516

RESUMO

Anaerobic digestion of manure is a common practice; however, the low biogas yield of manure can hamper the profitability of systems in small to medium farms. An increase in biogas yield could be achieved by co-digesting animal manure with co-substrates such as cheese whey. A Techno-economic assessment of anaerobic co-digestion of animal manure and cheese whey (cow, goat and sheep), has been carried out. The results obtained showed that for a farm with 250 adult cattle heads, the revenues generated in an anaerobic mono-digestion process are not able to offset the initial required investment. However, the co-digestion of manure with 30% of cheese whey showed a good economic performance and positive returns (Net Present values >0, Internal Rate of Return >11% and a Return of the investment in <10 years). Electricity selling price and biogas production are the key parameters to determine the profitability of the system.


Assuntos
Queijo , Esterco , Soro do Leite/metabolismo , Anaerobiose , Animais , Biocombustíveis/economia , Bovinos , Fazendas , Feminino , Cabras , Gado , Ovinos
2.
Bioresour Technol ; 291: 121863, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31376664

RESUMO

This study examined the influence of the application of brewery spent grain (BSG) on biogas production efficiency as well as its kinetics in the co-digestion of acid cheese whey (ACW) and sewage sludge (SS). The experiment was conducted in semi-flow anaerobic reactors under mesophilic conditions (35 °C) with different hydraulic retention times (HRT) of 16.7 d, 18 d and 20 d. The results indicate that the addition of BSG significantly enhanced the biogas yields, ensuring good process stability. The highest value of 0.54 m3 kg-1 VSadded was obtained at HRT of 16.7 d, while for ACW and SS it was only 0.50 m3 kg-1 VSadded at HRT 18 d. However, the decrease in the rate constant k occurred (0.07 h-1) as compared to the two-component system (0.096 h-1). The highest energy profit of 160% was enhanced for the three-substrate co-digestion, indicating it as a cost-effective solution.


Assuntos
Queijo , Grão Comestível/metabolismo , Esgotos , Soro do Leite/metabolismo , Anaerobiose , Biocombustíveis/análise , Grão Comestível/química , Especificidade por Substrato
3.
Bioresour Technol ; 289: 121722, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31323727

RESUMO

Batch dark fermentation tests were performed on sheep cheese whey without inoculum addition at different operating pHs, relating the type and production yields of the observed gaseous and liquid by-products to the evolution of fermentation. Cheese whey fermentation evolved over time in two steps, involving an initial conversion of carbohydrates to lactic acid, followed by the degradation of this to soluble and gaseous products including short-chain fatty acids (mainly acetic, butyric and propionic acids) and hydrogen. The operating pH affected the production kinetics and yields, as well as the fermentation pathways. By varying the duration of the fermentation process, different cheese whey exploitation strategies may be applied and oriented to the main production of lactic acid, hydrogen or other organic acids.


Assuntos
Biocombustíveis , Queijo , Soro do Leite/metabolismo , Fermentação , Hidrogênio/metabolismo , Concentração de Íons de Hidrogênio , Ácido Láctico/biossíntese
4.
Food Chem ; 297: 125005, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253325

RESUMO

Multiwalled carbon nanotubes molybdenum disulfide 3D nanocomposite (MWCNT-MoS2 NC) was successfully synthesized via eco-friendly hydrothermal method. The microstructural characterization of synthesized nanocomposite was carried out using different spectroscopic and microscopic techniques. Nanocomposite was activated using glutaraldehyde chemistry and used as a platform to immobilize Lens culinaris ß-galactosidase (Lsbgal) which resulted in 93% of immobilization efficiency. Attachment of Lsbgal onto nanocomposite was confirmed by AFM, FE-SEM, FTIR, and CLSM. The nanobiocatalyst showed broadening in operational pH and temperature working range. Remarkable increase in thermal stability was observed as compared to soluble enzyme. Nanobiocatalyst showed outstanding increase in storage stability, retained 92% of residual activity over a period of 8 months. This offers good reusability as it retained ∼50% residual activity up to 21 reuses and exhibited higher rate of lactose hydrolysis in whey. MWCNT-MoS2 NC conjugated to biomolecules can serve as a potential platform for fabrication of lactose biosensor.


Assuntos
Lactose/metabolismo , Lens (Planta)/enzimologia , Nanocompostos/química , Soro do Leite/metabolismo , beta-Galactosidase/metabolismo , Biocatálise , Dissulfetos/química , Estabilidade Enzimática , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Concentração de Íons de Hidrogênio , Molibdênio/química , Nanotubos de Carbono/química , Temperatura Ambiente , beta-Galactosidase/química
5.
J Agric Food Chem ; 67(22): 6257-6262, 2019 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-31117497

RESUMO

Lactose, the sugar contained in milk, has a low sweetness. We have constructed an efficient whole-cell catalyst (WCC) that can be grown on dairy waste and that is able to convert lactose into a mixture of sugars as sweet as sucrose. The WCC is based on Corynebacterium glutamicum ATCC13032, which has been engineered to metabolize lactose, to express xylose and arabinose isomerase, and to eliminate byproduct formation. When introduced in concentrated cheese whey permeate, its content of 98 g/L lactose was completely hydrolyzed and the liberated sugars partially isomerized into 23.5 g/L fructose and 20.4 g/L tagatose, which corresponds to a 49% conversion of the glucose and a 44% conversion of galactose. The latter is similar to what can be obtained using purified enzymes. The new technology enables better resource utilization and allows for dairy waste to be converted into a valuable food sweetener with many potential uses.


Assuntos
Corynebacterium glutamicum/metabolismo , Lactose/metabolismo , Açúcares/metabolismo , Edulcorantes/metabolismo , Animais , Catálise , Bovinos , Corynebacterium glutamicum/genética , Isomerismo , Lactose/análise , Engenharia Metabólica , Açúcares/química , Edulcorantes/química , Soro do Leite/química , Soro do Leite/metabolismo
6.
Appl Microbiol Biotechnol ; 103(9): 3737-3751, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30919101

RESUMO

The aim of this research was to analyze the antioxidant and prebiotic properties of lactobionic acid and to develop a method of producing it from whey using the bacterium Pseudomonas taetrolens. Prebiotic properties were tested with selected bacterial strains that exhibit probiotic properties, while the antioxidant efficacy was tested using cold-pressed rapeseed oil. A particularly evident prebiotic effect was observed with the bacterium Lactobacillus fermentum with a lactobionic acid concentration of 16 mg/cm3. The growth curves of microorganisms in a substrate with various levels of lactobionic acid showed similarities between Lactococcus lactis, Lactobacillus acidophilus DSM 20242, Lactobacillus acidophilus L-AH1, Lactobacillus acidophilus NCDO, Lactobacillus delbrueckii A, Lactobacillus casei, Lactobacillus casei Shirota, Bifidobacterium bifidum DSM 20215, and Bifidobacterium bifidum DSM 20456, where a short logarithmic growth phase could be distinguished, in comparison to the growth of Lactobacillus fermentum and Lactobacillus acidophilus CH-5, where the logarithmic growth phase was extended. Bifidobacterium bifidum DSM 20082 and Bifidobacterium bifidum DSM 20239 form a separate group. The greater the amount of lactobionic acid added, the higher its activity. The greatest oxidation inhibition efficacy in rapeseed oil was recorded on day 10 of storage at 60 °C with an acid content of 10 mg/cm3. Expressed as a percentage reduction of peroxide value, this effect was 19.6%. The best result for preparations of lactobionic acid were found at 1 cm3 (22.03 mg/cm3), amounting to 7.3% on day 10 of the rapeseed oil thermostat test.


Assuntos
Antioxidantes/química , Antioxidantes/metabolismo , Dissacarídeos/química , Dissacarídeos/metabolismo , Prebióticos/análise , Pseudomonas/metabolismo , Soro do Leite/microbiologia , Temperatura Alta , Lactobacillus fermentum/crescimento & desenvolvimento , Lactobacillus fermentum/metabolismo , Oxirredução , Peróxidos/química , Óleo de Brassica napus/química , Soro do Leite/metabolismo , Proteínas do Soro do Leite/metabolismo
7.
Microb Cell Fact ; 18(1): 51, 2019 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-30857537

RESUMO

BACKGROUND: Delactosed whey permeate (DWP) is a side stream of whey processing, which often is discarded as waste, despite of its high residual content of lactose, typically 10-20%. Microbial fermentation is one of the most promising approaches for valorizing nutrient rich industrial waste streams, including those generated by the dairies. Here we present a novel microbial platform specifically designed to generate useful compounds from dairy waste. As a starting point we use Corynebacterium glutamicum, an important workhorse used for production of amino acids and other important compounds, which we have rewired and complemented with genes needed for lactose utilization. To demonstrate the potential of this novel platform we produce ethanol from lactose in DWP. RESULTS: First, we introduced the lacSZ operon from Streptococcus thermophilus, encoding a lactose transporter and a ß-galactosidase, and achieved slow growth on lactose. The strain could metabolize the glucose moiety of lactose, and galactose accumulated in the medium. After complementing with the Leloir pathway (galMKTE) from Lactococcus lactis, co-metabolization of galactose and glucose was accomplished. To further improve the growth and increase the sugar utilization rate, the strain underwent adaptive evolution in lactose minimal medium for 100 generations. The outcome was strain JS95 that grew fast in lactose mineral medium. Nevertheless, JS95 still grew poorly in DWP. The growth and final biomass accumulation were greatly stimulated after supplementation with NH4+, Mn2+, Fe2+ and trace minerals. In only 24 h of cultivation, a high cell density (OD600 of 56.8 ± 1.3) was attained. To demonstrate the usefulness of the platform, we introduced a plasmid expressing pyruvate decarboxylase and alcohol dehydrogenase, and managed to channel the metabolic flux towards ethanol. Under oxygen-deprived conditions, non-growing suspended cells could convert 100 g/L lactose into 46.1 ± 1.4 g/L ethanol in DWP, a yield of 88% of the theoretical. The resting cells could be re-used at least three times, and the ethanol productivities obtained were 0.96 g/L/h, 2.2 g/L/h, and 1.6 g/L/h, respectively. CONCLUSIONS: An efficient process for producing ethanol from DWP, based on C. glutamicum, was demonstrated. The results obtained clearly show a great potential for this newly developed platform for producing value-added chemicals from dairy waste.


Assuntos
Corynebacterium glutamicum/metabolismo , Etanol/metabolismo , Resíduos Industriais , Lactose/metabolismo , Soro do Leite/metabolismo , Corynebacterium glutamicum/genética , Indústria de Laticínios , Fermentação
8.
Int Microbiol ; 22(2): 265-277, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30810989

RESUMO

We aimed at isolating and characterising microorganisms present in human breast milk with probiotic potential. In an 8-week postpartum sampling period, two strains of bifidobacteria (Bifidobacterium longum LM7a and Bifidobacterium dentium LM8a') and four strains of lactobacilli were isolated, all during the first 4-week postpartum. B. longum LM7a and B. dentium LM8a', together with four strains previously isolated from breast milk (Bifidobacterium lactis INL1, INL2, INL4 and INL5), were considered for further studies. Susceptibility of the strains to tetracycline, erythromycin, clindamycin, streptomycin, vancomycin and chloramphenicol was evaluated and the isolates exhibited, in general, the same properties as previously reported for bifidobacteria. All isolates showed low hydrophobicity and B. lactis and B. longum strains had satisfactory resistance to gastric digestion and bile shock, but not to pancreatin. B. lactis INL1, B. longum LM7a and B. dentium LM8a' were selected for some comparative technological studies. In particular, B. lactis INL1 displayed technological potential, with satisfactory growth in cheese whey-based media in biofermentor and resistance to freeze-drying, accelerated storage conditions and simulated gastric digestion.


Assuntos
Bifidobacterium/isolamento & purificação , Meios de Cultura/química , Lactobacillus/isolamento & purificação , Leite Humano/microbiologia , Probióticos/efeitos adversos , Probióticos/isolamento & purificação , Soro do Leite/metabolismo , Antibacterianos/farmacologia , Bifidobacterium/efeitos dos fármacos , Bifidobacterium/crescimento & desenvolvimento , Bifidobacterium/metabolismo , Ácidos e Sais Biliares/toxicidade , Feminino , Ácido Gástrico/metabolismo , Humanos , Lactobacillus/efeitos dos fármacos , Lactobacillus/crescimento & desenvolvimento , Lactobacillus/metabolismo , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Pancreatina/toxicidade
9.
Bioresour Technol ; 279: 74-83, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30711755

RESUMO

The objective of this study was to investigate the potential of supplementing ethanol and lactic acid as electron donors in reverse ß-oxidation for short chain carboxylic acids chain elongation during anaerobic fermentation of acid whey. Best results were achieved when lactic acid was added at concentration of 300 mM. It resulted in medium chain carboxylic acids (MCCAs) concentration of 5.0 g/L. In the trials with ethanol addition, the overall yield was 20% lower. Subsequently liquid-liquid extraction with ionic liquids (ILs) was investigated as a potential purification method of caproic acid. The most promising, with respect to recovery of caproic acid, was piperazinium IL [C1C1C10Ppz][NTF2], however, the selectivity was only 0.39. Less effective [C1C1C6Ppz][NTF2] recovered 85.9% of caproic acid while reaching a higher selectivity of 0.53. Technoeconomic model revealed that to meet the conservative value of $2.25 per kg of caproic acid, the downstream processing should not exceed $0.65 per kg.


Assuntos
Caproatos/metabolismo , Soro do Leite/metabolismo , Reatores Biológicos , Elétrons , Etanol/metabolismo , Fermentação
10.
Microb Biotechnol ; 12(3): 487-501, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30702206

RESUMO

Polyhydroxyalkanoates (PHAs) are polyesters of microbial origin that can be synthesized by prokaryotes from noble sugars or lipids and from complex renewable substrates. They are an attractive alternative to conventional plastics because they are biodegradable and can be produced from renewable resources, such as the surplus of whey from dairy companies. After an in silico screening to search for ß-galactosidase and PHA polymerase genes, several bacteria were identified as potential PHA producers from whey based on their ability to hydrolyse lactose. Among them, Caulobacter segnis DSM 29236 was selected as a suitable strain to develop a process for whey surplus valorization. This microorganism accumulated 31.5% of cell dry weight (CDW) of poly(3-hydroxybutyrate) (PHB) with a titre of 1.5 g l-1 in batch assays. Moreover, the strain accumulated 37% of CDW of PHB and 9.3 g l-1 in fed-batch mode of operation. This study reveals this species as a PHA producer and experimentally validates the in silico bioprospecting strategy for selecting microorganisms for waste re-valorization.


Assuntos
Caulobacter/genética , Caulobacter/metabolismo , Microbiologia Industrial , Poli-Hidroxialcanoatos/metabolismo , Soro do Leite/metabolismo , Biotransformação , Biologia Computacional , Mineração de Dados
11.
Bioresour Technol ; 275: 375-385, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30599281

RESUMO

This study investigates the efficiency in methane production of lab-scale mesophilic (37 °C) and thermophilic (54 °C) continuous stirred tank reactors fed with cheese whey at different operational conditions. Results showed that whey mono-digestion was feasible at mesophilic conditions, while at thermophilic conditions frequent acidification incidents were recorded. The limited buffer capacity of the influent feedstock was responsible for the unstable anaerobic digestion process. The co-digestion of cheese whey with cattle manure maintained the pH levels higher than 7.0, and therefore, stable methane production rates were achieved without any significant accumulation of volatile fatty acids. An additional enhancement of the methane productivity was achieved by in-situ H2 dispersion. Microbial community composition was investigated using high-throughput 16S rRNA gene amplicon sequencing and results were correlated with process parameters. Hydrogenotrophic methanogens were the dominant archaea during the whole experiment at mesophilic and thermophilic conditions.


Assuntos
Queijo , Soro do Leite/metabolismo , Anaerobiose , Reatores Biológicos , Queijo/microbiologia , Euryarchaeota/genética , Ácidos Graxos Voláteis/biossíntese , Esterco , RNA Ribossômico 16S/genética
12.
J Dairy Sci ; 102(3): 2283-2297, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30660422

RESUMO

Postpartum dietary supplementation of gluconeogenic precursors may improve the plasma metabolite profile of dairy cows, reducing metabolic disorders and improving lactation performance. The objective of this trial was to examine the effects of supplementation with fermented ammoniated condensed whey (FACW) postpartum on lactation performance and on profile of plasma metabolites and hormones in transition dairy cows. Individually fed multiparous Holstein cows were blocked by calving date and randomly assigned to control (2.9% dry matter of diet as soybean meal; n = 20) or FACW (2.9% dry matter of diet as liquid GlucoBoost, Fermented Nutrition, Luxemburg, WI; n = 19) dietary treatments. Treatments were offered from 1 to 45 d in milk (DIM). Cows were milked twice a day. Dry matter intake and milk yield were recorded daily and averaged weekly. Individual milk samples from 2 consecutive milkings were obtained once a week for component analysis. Rumen fluid was collected (n = 3 cows/treatment) at 4 time points per day at 7 and 21 DIM. Blood samples were collected within 1 h before feeding time for metabolite analysis and hyperketonemia diagnosis. Supplementation of FACW improved feed efficiency relative to control; this effect may be partially explained by a marginally significant reduction in dry matter intake from wk 3 to 7 for FACW-supplemented cows with no detected FACW-driven changes in milk yield, milk protein yield, and milk energy output compared with control. Also, there was no evidence for differences in intake of net energy for lactation, efficiency of energy use, energy balance, or body weight or body condition score change from calving to 45 DIM between treatments. Supplementation of FACW shifted rumen measures toward greater molar proportions of propionate and butyrate, and lesser molar proportions of acetate and valerate. Cows supplemented with FACW had greater plasma glucose concentrations in the period from 3 to 7 DIM and greater plasma insulin concentrations compared with control. Plasma nonesterified fatty acid and ß-hydroxybutyrate concentrations were decreased in cows supplemented with FACW compared with control cows in the period from 3 to 7 DIM. These findings indicate that FACW may have improved the plasma metabolite profile immediately postpartum in dairy cows. Additionally, supplementation of FACW resulted in improved feed efficiency as accessed by measures of milk output relative to feed intake.


Assuntos
Compostos de Amônio/metabolismo , Bovinos/fisiologia , Hormônios/sangue , Período Pós-Parto/fisiologia , Soro do Leite/metabolismo , Ração Animal/análise , Animais , Análise Química do Sangue/veterinária , Dieta/veterinária , Suplementos Nutricionais/análise , Feminino , Fermentação , Período Pós-Parto/efeitos dos fármacos , Soro do Leite/administração & dosagem
13.
J Dairy Sci ; 102(3): 2044-2050, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30660415

RESUMO

Acid whey, a by-product of strained yogurt production, represents a disposal challenge for the dairy industry. Utilization schemes are currently limited; however, acid whey contains valuable components that could be used to create value-added products. One potential scheme would be the fermentation of acid whey into an alcoholic beverage. Sour beers are gaining popularity and acid whey, which is sour to begin with, could provide a new product opportunity. However, the main sugar of acid whey, lactose, cannot be fermented by the traditional brewer's yeast, Saccharomyces cerevisiae. It has been reported that barley contains enzymes capable of hydrolyzing lactose to glucose and galactose, which are fermentable by S. cerevisiae. We investigated whether a barley-based mash resulted in detectable hydrolysis of lactose into sugars fermentable by S. cerevisiae. We demonstrated the ability to hydrolyze lactose in acid whey using a barley-based mash, resulting in the average release of 3.70 g/L of glucose. Additionally, the subsequent liquid was fermented by S. cerevisiae to an average ethanol concentration of 3.23% alcohol by volume. This work demonstrates the ability to hydrolyze the lactose in acid whey using barley and the opportunity to use acid whey as a fermentable sugar source in beer production.


Assuntos
Etanol/metabolismo , Hordeum/enzimologia , Lactose/metabolismo , Saccharomyces cerevisiae/metabolismo , Soro do Leite/metabolismo , Reatores Biológicos
14.
J Agric Food Chem ; 67(3): 829-835, 2019 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-30638366

RESUMO

In this study, the dual production of valuable d-tagatose and bioethanol from lactose and cheese whey powder is presented. First, a one-pot biosynthesis involving lactose hydrolysis and d-galactose isomerization for d-tagatose production was established using crude enzymes of recombinant Escherichia coli with l-arabinose isomerase (L-AI) at 50 °C. Compared to the current enzymatic system, only L-AI was overexpressed, because of the unexpectedly thermotolerant ß-galactosidase in E. coli BL21(DE3). Moreover, this high temperature rendered the d-glucose catabolism of E. coli inactive, while retaining all fermentable sugars for bioethanol fermentation. Thereafter, the mixed sugar syrup was fermented by Saccharomyces cerevisiae NL22. A total of 23.5 g/L d-tagatose and 26.9 g/L bioethanol was achieved from cheese whey powder containing 100 g/L lactose. This bioprocess not only provides an efficient method for the functionalization of byproduct whey, but also offsets the high production cost of d-tagatose and bioethanol.


Assuntos
Queijo/microbiologia , Escherichia coli/metabolismo , Etanol/metabolismo , Hexoses/metabolismo , Proteínas do Soro do Leite/metabolismo , Soro do Leite/microbiologia , Aldose-Cetose Isomerases/genética , Aldose-Cetose Isomerases/metabolismo , Biotransformação , Queijo/análise , Escherichia coli/enzimologia , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Fermentação , Concentração de Íons de Hidrogênio , Lactose/metabolismo , Pós/química , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Soro do Leite/metabolismo
15.
Bioresour Technol ; 272: 70-76, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30312870

RESUMO

Cheese whey, produced from coagulation of milk during cheese manufacture, is a major environmental pollutant. The most abundant component in cheese whey is lactose, which is a potential resource for various value-added chemicals. Here, a two-step bioprocess using Saccharomyces cerevisiae and Gluconobacter oxydans to bioconvert cheese whey into ethanol and galactonic acid was first proposed. First, the lactose in cheese whey powder was pretreated with ß-galactosidase to obtain glucose and galactose. Subsequently, the glucose was selectively fermented to ethanol by S. cerevisiae to enable G. oxydans-mediated biooxidation of galactose to galactonic acid. Finally, approximately 110 g ethanol, 320 g galactonate, and 150 g mixed protein (residual cheese whey protein and cell protein) was produced from 1 kg CWP. These results are suggestive of alternative methods for management of cheese whey, which may reduce its impact on the environment and result in production of value-added biochemicals.


Assuntos
Queijo , Etanol/metabolismo , Açúcares Ácidos/metabolismo , Proteínas do Soro do Leite/metabolismo , Soro do Leite/metabolismo , Reatores Biológicos , Queijo/análise , Fermentação , Galactose/metabolismo , Gluconobacter oxydans/metabolismo , Lactose/metabolismo , Pós , Saccharomyces cerevisiae/metabolismo , Soro do Leite/química , Proteínas do Soro do Leite/química
16.
J Dairy Sci ; 102(1): 87-99, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30527981

RESUMO

Whey, the main by-product of the dairy industry, is frequently disposed of in the environment without any treatment due to the high cost of this process. Alternatively, whey can be used as a medium to culture lactic acid bacteria and produce value-added products such as bacteriocins. In this work, we attempted to improve bacteriocin production by Lactobacillus plantarum ST16Pa in a whey powder formulation supplemented with additional sources of carbon, nitrogen, and vitamin B12 at different levels and varying the agitation intensity according to a Plackett-Burman experimental design. Only the addition of tryptone positively influenced the production of this bacteriocin. The results allowed us to identify a supplemented whey formulation, comprising 150 g/L of whey total solids plus 10 g/L of tryptone and soybean extract, whose fermentation by Lb. plantarum ST16Pa in shake flasks under agitation at 150 rpm led to a cell-free supernatant with an antimicrobial activity against Listeria innocua 6a CLIST 2865 (inhibition zone of 13.23 mm) close to that previously obtained in de Man, Rogosa and Sharpe medium by other authors. These results are significant considering that the same strain cultured in cheese whey did not previously display any antimicrobial activity.


Assuntos
Bacteriocinas/biossíntese , Lactobacillus plantarum/metabolismo , Soro do Leite/metabolismo , Animais , Bacteriocinas/isolamento & purificação , Bacteriocinas/farmacologia , Reatores Biológicos/normas , Queijo/microbiologia , Quimotripsina/metabolismo , Fermentação , Ácido Láctico/análise , Lactobacillus plantarum/efeitos dos fármacos , Lactobacillus plantarum/crescimento & desenvolvimento , Lactose/análise , Listeria/metabolismo , Pós , Pronase/metabolismo , Tripsina/metabolismo , Soro do Leite/química , Proteínas do Soro do Leite/metabolismo
17.
Food Funct ; 9(7): 3688-3697, 2018 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-29969130

RESUMO

The aim of this study was to evaluate the biological and antimicrobial activities of commercial freeze-dried whey fermented by lactic acid bacteria in order to valorize this high polluting liquid waste of the dairy industry. Freeze-dried whey was fermented by different strains of Lactobacillus plantarum (CECT 220, 221, 748) at three different times of fermentation (24, 48, 72 h). Afterwards, the extract was purified on centricon amicon with a cut-off of 3 kDa to obtain a permeate consisting of small bioactive compounds reported in the literature to show greater bioactivity. The purified and diluted samples were subjected to the biological and antimicrobial tests for the evaluation of antioxidant, antihypertensive, iron binding, and antifungal activities and identification of phenolic compounds. The results highlighted a radical cation scavenging activity ranging from 1.415 to 2.083 mmol trolox equivalents TE per kg of dry weight, a percentage of iron binding capacity ranging between 23-55% and a percentage of ACE inhibitory activity ranging between 67-85%. The optimal biological activity was obtained from whey fermented by L. plantarum 220 for all the assays performed, except for the iron chelating activity. Furthermore, the antifungal analysis showed a good activity against the mycotoxigenic fungi belonging to Fusarium generum (F. moniliformis, F. graminearum and F. verticillioides), while a slight activity was obtained for Aspergillus and Penicillium generum. This antifungal activity could be correlated to the production of phenolic compounds during fermentation. The obtained results support the hypothesis of using whey as a functional ingredient to improve food preservation.


Assuntos
Antifúngicos/metabolismo , Antifúngicos/farmacologia , Lactobacillus plantarum/metabolismo , Soro do Leite/microbiologia , Antifúngicos/química , Fermentação , Liofilização , Fungos/efeitos dos fármacos , Lactobacillus plantarum/classificação , Lactobacillus plantarum/genética , Espectrometria de Massas , Fenóis/química , Fenóis/metabolismo , Fenóis/farmacologia , Soro do Leite/química , Soro do Leite/metabolismo
18.
Appl Microbiol Biotechnol ; 102(18): 8023-8033, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29946931

RESUMO

Whey from cheese and yoghurt production operations contains useful constituents such as whey protein and lactose. However, the separation and extraction processes are difficult and costly, and hence, whey has limited end user demand and is typically disposed of as waste. Treatment and disposal of these high BOD wastes are both energy intensive and expensive. However, improper disposal of these wastes can pollute surface and ground water resources. The use of these low or negative cost substrates for the production of value-added products such as acetic acid and propylene glycol (PG) is of great significance in changing overhead costs to revenue streams. The present study focuses on bioproduction of acetic acid and PG from whey lactose and whey powder containing lactose and protein as an alternative to high cost nutritive medium. It was found that Lactobacillus buchneri, an acid-tolerant bacterium, is able to ferment lactose at pH ~ 4.2 to low molecular weight compounds such as acetic acid and PG each at 25-30 g L-1 concentration when using lactose as a major carbon substrate. The typical molar ratio of acetic acid to PG was close to 1:1 at the end of fermentation. The productivity of acetic acid and PG was improved using a high cell density fermentation with cotton cheesecloth as an immobilization matrix. The use of whey powder with immobilized fermentation system showed a similar performance to that of cultures fed with pure lactose at pH 4.2, resulting in a 57% conversion of lactose in whey to acetate and PG in total, against a stoichiometric maximum of 72%.


Assuntos
Ácido Acético/metabolismo , Microbiologia Industrial/métodos , Lactobacillus/metabolismo , Propilenoglicol/metabolismo , Soro do Leite/microbiologia , Meios de Cultura/metabolismo , Fermentação , Ácido Láctico/metabolismo , Lactose/metabolismo , Resíduos/análise , Soro do Leite/metabolismo , Proteínas do Soro do Leite/metabolismo
19.
J Dairy Sci ; 101(3): 1872-1882, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29290443

RESUMO

Lactose is a main by-product in the cheese industry. Many attempts have been made to convert the lactose to high value-added products, including epilactose. Epilactose is a valuable prebiotic and can be epimerized from lactose with cellobiose 2-epimerase (CEase). The objective of the present work was to construct a food-grade recombinant Bacillus subtilis that produces CEase from Thermoanaerobacterium saccharolyticum. The CEase was expressed in B. subtilis without antibiotic resistance genes. After fermentation, the maximum volumetric activity of the fermented broth was more than 7 U/mL. The activity of the recombinant B. subtilis was increased by up to 3.7 fold after ethanol permeabilization. Then, 66.9 ± 0.7 g/L of epilactose was produced from 300 g/L of whey powder solution in 1 h with 13.3 U/mL of permeabilized biocatalyst. In addition, an enzymatic route including degradation of the lactose, yeast fermentation, and cation exchange chromatography was described to further purify the produced epilactose from lactose. Finally, epilactose with a purity >98% was produced from 300 g/L of lactose with a yield of 24.0%. In conclusion, neither antibiotics nor pathogenic bacteria were used throughout the epilactose production and purification procedure.


Assuntos
Bacillus subtilis/genética , Carboidratos Epimerases/genética , Dissacarídeos/biossíntese , Lactose/química , Thermoanaerobacterium/enzimologia , Bacillus subtilis/enzimologia , Carboidratos Epimerases/metabolismo , Clonagem Molecular , Dissacarídeos/isolamento & purificação , Fermentação , Prebióticos , Thermoanaerobacterium/genética , Soro do Leite/metabolismo
20.
Food Funct ; 9(1): 227-233, 2018 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-29168514

RESUMO

Modulation of regional growth within specific segments of the bowel may have clinical value for several gastrointestinal conditions. We therefore examined the effects of different dietary protein sources on regional gut growth and luminal growth factor bioactivity as potential therapies. Rats were fed for 14 days on isonitrogenous and isocaloric diets comprising elemental diet (ED) alone (which is known to cause gut atrophy), ED supplemented with casein or whey or a soya protein-rich feed. Effects on regional gut growth and intraluminal growth factor activity were then determined. Despite calorie intake being similar in all groups, soya rich feed caused 20% extra total body weight gain. Stomach weight was highest on soya and casein diets. Soya enhanced diet caused greatest increase in small intestinal weight and preserved luminal growth factor activity at levels sufficient to increase proliferation in vitro. Regional small intestinal proliferation was highest in proximal segment in ED fed animals whereas distal small intestine proliferation was greater in soya fed animals. Colonic weight and proliferation throughout the colon was higher in animals receiving soya or whey supplemented feeds. We conclude that specific protein supplementation with either soya, casein or whey may be beneficial to rest or increase growth in different regions of the bowel through mechanisms that include differentially affecting luminal growth factor bioactivity. These results have implications for targeting specific regions of the bowel for conditions such as Crohn's disease and chemotherapy.


Assuntos
Caseínas/metabolismo , Colo/crescimento & desenvolvimento , Colo/metabolismo , Intestino Delgado/crescimento & desenvolvimento , Intestino Delgado/metabolismo , Proteínas de Soja/metabolismo , Animais , Colo/lesões , Colo/fisiopatologia , Proteínas na Dieta , Alimentos Formulados/efeitos adversos , Intestino Delgado/lesões , Intestino Delgado/fisiopatologia , Masculino , Ratos , Ratos Sprague-Dawley , Regeneração , Soja/metabolismo , Soro do Leite/metabolismo
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