The high expression of Aspergillus pseudoglaucus protease in Escherichia coli for hydrolysis of soy protein and milk protein

Abstract

The hydrolysates of soy protein and milk protein are nutritional and functional food ingredients. Aspergillus pseudoglaucus aspergillopepsin I (App) is an acidic protease, including signal peptide, propeptide, and catalytic domain. Here, we cloned the catalytic domain App with or without propeptide in Escherichia coli. The results showed that the App without propeptide was not expressed or did not exhibit activity and App with propeptide (proApp) was highly expressed with a specific activity of 903?U/mg. Moreover, the denaturation temperature of proApp was 4.1?°C higher than App’s. The proApp showed 104?U/mg and 252?U/mg hydrolysis activities towards soy protein and milk protein under acidic conditions. By RP-HPLC analysis, the peptides obtained from the hydrolysates of soy protein and milk protein were hydrophilic peptides. This work first demonstrates efficient proteolysis of soy protein and milk protein through the functional expression of full-length proApp, which will likely have valuable industrial applications.     

Comparison of exopolysaccharide production by strains of Lactobacillus rhamnosus and Lactobacillus paracasei grown in chemically defined medium and milk

Exopolysaccharide (EPS) production was compared among three strains of lactobacilli. Lactobacillus rhamnosus strain 9595M can be classified among the highest EPS-producing strains of lactic acid bacteria reported to date with a maximum EPS production of 1275 mg L⁻¹. Under controlled pH, no significant differences in the quantity of EPS produced could be detected between carbon source (glucose or lactose) or fermentation temperature (32 or 37°C). In milk, strains ATCC 9595M and R produced more than 280 mg L⁻¹ EPS whereas strain Type V produced less than 80 mg L⁻¹ EPS. Journal of Industrial Microbiology & Biotechnology (2000) 24, 251–255. Received 10 September 1999/ Accepted in revised form 22 December 1999     

Inactivation effect of X-ray treatments on Cronobacter species (Enterobacter sakazakii) in tryptic soy broth, skim milk, low-fat milk and whole-fat milk*

Aims:  To determine the inactivation effect of X-ray treatments on Cronobacter ( E. sakazakii ) in tryptic soy broth (TSB), skim milk (0% fat), low-fat milk (1% and 2%) and whole-fat milk (3·5%).
Methods and Results:  X-rays were produced using the RS 2400 generator system (Rad Source Technologies Inc.). Cronobacter (in TSB), inoculated skim milk (0% fat), low-fat milk (1% and 2% fat) and whole-fat milk (3·5% fat) were treated with 0·0, 0·1, 0·5, 0·75, 1·0, 2·0, 3·0, 4·0, 5·0 and 6·0 kGy X-ray doses. Surviving bacteria in the TSB and inoculated milk, before and after treatment, were enumerated using plating method onto trypticase soy agar. Greater than 7·0-log CFU reduction in Cronobacter population was observed with 4·0, 5·0, 6·0, 6·0 and 6·0 kGy X-ray in the TSB, skim milk, 1% fat milk, 2% fat milk and 3·5% fat milk, respectively.
Conclusions:  Treatment with X-rays significantly ( P  <   0·05) reduced Cronobacter to less than detectable limits (<1 log CFU ml⁻¹) in skim milk at 5·0 kGy and milk with 1% fat content and greater at 6·0 kGy dose levels. The D-value for Cronobacter in TSB was significantly ( P  <   0·05) lower than those in milk samples.
Significance and Impact of the Study:  Treatment with X-rays could be an effective and safe alternative technology to control pathogenic bacteria ( Cronobacter ) in the dairy industry.     

食用真菌发酵豆浆过程中对豆浆中几种生物活性物质的影响

本实验以灵芝、金耳以及冬虫夏草作为发酵菌种,选用豆浆为基本原料配制培养基,在发酵过程中定时取样并测定其中几种生物活性物质的含量,分析各生物活性物质在发酵过程中的变化。研究结果表明,三种食用真菌发酵豆浆的发酵液中总游离型大豆异黄酮含量在发酵过程中均缓慢上升并分别在发酵72 h、24 h和36 h达到最高,与发酵初期相比分别增加了31.81μg/m L、19.05μg/m L和15.71μg/m L;三种食用真菌发酵液中蛋白质含量随着发酵时间的推移而降低的同时氨基酸含量均有增加,且发酵液中的肽主要是分子量范围在300 Da~1 500 Da之间的具有较高生物活性的小分子肽,发酵液中的必需氨基酸含量以及占总氨基酸含量的比值均有增加。本实验探究了食用真菌发酵豆浆过程中生物活性物质的变化,为日后的富集游离型大豆异黄酮、多肽以及氨基酸等生物活性物质实验提供依据,并为工业化生产提供实践基础。     

Predicting grass dry matter intake,milk yield and milk fat and protein yield of spring calving grazing dairy cows during the grazing season

Predicting the grass dry matter intake (GDMI), milk yield (MY) or milk fat and protein yield (milk solids yield (MSY)) of the grazing dairy herd is difficult. Decisions with regard to grazing management are based on guesstimates of the GDMI of the herd, yet GDMI is a critical factor influencing MY and MSY. A data set containing animal, sward, grazing management and concentrate supplementation variables recorded during weeks of GDMI measurement was used to develop multiple regression equations to predict GDMI, MY and MSY. The data set contained data from 245 grazing herds from 10 published studies conducted at Teagasc, Moorepark. A forward stepwise multiple regression technique was used to develop the multiple regression equations for each of the dependent variables (GDMI, MY, MSY) for three periods during the grazing season: spring (SP; 5 March to 30 April), summer (SU; 1 May to 31 July) and autumn (AU; 1 August to 31 October). The equations generated highlighted the importance of different variables associated with GDMI, MY and MSY during the grazing season. Peak MY was associated with an increase in GDMI, MY and MSY during the grazing season with the exception of GDMI in SU when BW accounted for more of the variation. A higher body condition score (BCS) at calving was associated with a lower GDMI in SP and SU and a lower MY and MSY in all periods. A higher BCS was associated with a higher GDMI in SP and SU, a higher MY in SU and AU and a higher MSY in all periods. The pre-grazing herbage mass of the sward (PGHM) above 4 cm was associated with a quadratic effect on GDMI in SP, on MY in SP and SU and on MSY in SU. An increase in daily herbage allowance (DHA) above 4 cm was associated with an increase in GDMI in AU, an increase in MY in SU and AU and MSY in AU. Supplementing grazing dairy cows with concentrate reduced GDMI and increased MY and MSY in all periods. The equations generated can be used by the Irish dairy industry during the grazing season to predict the GDMI, MY and MSY of grazing dairy herds.     

Affinity immunosensor for milk progesterone: identification of critical parameters

The effects of several experimental parameters on the performance characteristics of a competitive-type immunochromatographic assay of milk progesterone were studied. Increasing the size of the colloidal gold particles used as a label increased both maximal signal obtained and sensitivity of the assay measured as slope of the progesterone standard curve. The concentration of the antibody used to prepare the detection zone was found to be a critical factor, in that low concentrations of antibody resulted in a poor sensitivity. The compatibilities of various buffer systems with the assay were studied. The assay worked well with buffers having a broad pH range of 4·5–8·5.     

Pasture intake and milk production of dairy cows rotationally grazing on multi-species swards

Increasing plant species diversity has been proposed as a means for enhancing annual pasture productivity and decreasing seasonal variability of pasture production facing more frequent drought scenarios due to climate change. Few studies have examined how botanical complexity of sown swards affects cow performance. A 2-year experiment was conducted to determine how sward botanical complexity, from a monoculture of ryegrass to multi-species swards (MSS) (grasses-legumes-forb), affect pasture chemical composition and nutritive value, pasture dry matter (DM) intake, milk production and milk solids production of grazing dairy cows. Five sward species: perennial ryegrass (L as Lolium), white clover and red clover (both referred to as T as Trifolium because they were always sown together), chicory (C as Cichorium) and tall fescue (F as Festuca) were assigned to four grazing treatments by combining one (L), three (LT), four (LTC) or five (LTCF) species. Hereafter, the LT swards are called mixed swards as a single combination of ryegrass and clovers, whereas LTC and LTCF swards are called MSS as a combination of at least four species from three botanical families. The experimental area (8.7 ha) was divided into four block replicates with a mineral nitrogen fertilisation of 75 kg N/ha per year for each treatment. In total, 13 grazing rotations were carried out by applying the same grazing calendar and the same pasture allowance of 19 kg DM/cow per day above 4 cm for all treatments. Clover represented 20% of DM for mixed and MSS swards; chicory represented 30% of DM for MSS and tall fescue represented 10% of DM for LTCF swards. Higher milk production (+1.1 kg/day) and milk solids production (+0.08 kg/day) were observed for mixed swards than for ryegrass swards. Pasture nutritive value and pasture DM intake were unaffected by the inclusion of clover. Pasture DM, organic matter and NDF concentrations were lower for MSS than for mixed swards. Higher milk production (+0.8 kg/day), milk solids production (+0.04 kg/day) and pasture DM intake (+1.5 kg DM/day) were observed for MSS than for mixed swards. These positive effects of MSS were observed for all seasons, but particularly during summer where chicory proportion was the highest. In conclusion, advantages of grazing MSS on cow performance were due to the cumulative effect of improved pasture nutritive value and increased pasture DM intake that raised milk production and milk solids production.     

Human hemoglobin adsorption onto colloidal cerium oxide nanoparticles: a new model based on zeta potential and spectroscopy measurements

The nanoparticle (NP)-induced conformational changes of protein and NP agglomeration have gained a remarkable interest in medical and biotechnological fields. Herein, the effect of human hemoglobin (Hb) on the colloidal stability of cerium oxide NP (CNP) was investigated by dynamic light scattering (DLS), zeta potential, and TEM analysis. In addition, the effect of CNP on the heme degradation and structural changes of Hb was studied using fluorescence, circular dichroism (CD), and UV–visible (UV–vis) spectroscopic methods. DLS and TEM analysis showed that the presence of Hb can increase the mean diameter of CNP. Zeta potential measurements revealed that CNP demonstrated a higher charge distribution relative to CNP/Hb complex. Besides, fluorescence studies indicated that two fluorescent heme degradation products are revealed during the interaction of CNP with Hb. Near UV-CD spectroscopy also showed that the microenvironmental changes of heme groups occur after interaction of Hb with CNP. The result of thermal behavior of Hb confirmed the structural changes of protein, which referred to decrease in the Hb stability in the presence of CNP. Indeed, the finding related to structural and functional changes of Hb induced by CNP may be crucial to obtain information regarding the side effects of NPs. Finally, this data reveal much insight into the effects of the interaction on protein structural changes and NP agglomeration, and can correlate the zeta potential of NP-protein complexes with the nature of the principle NP-protein interaction.     

Severe feed restriction increases permeability of mammary gland cell tight junctions and reduces ethanol stability of milk

A total of twelve lactating Jersey cows were used in a 5-week experiment to determine the effects of severe feed restriction on the permeability of mammary gland cell tight junctions (TJs) and its effects on milk stability to the alcohol test. During the first 2 weeks, cows were managed and fed together and received the same diet according to their nutritional requirements (full diet: 15 kg of sugar cane silage; 5.8 kg of alfalfa hay; 0.16 kg of mineral salt and 6.2 kg of concentrate). In the 3rd week, animals were distributed into two groups of six cows each. One group received the full diet and the other a restricted diet (50% of the full diet). In the 4th and 5th weeks, all animals received the full diet again. Milk composition and other attributes, such as titratable acidity, ethanol stability, pH, density and somatic cell count (SCC) were evaluated. Cortisol levels indicated the stress condition of the cows. Plasma lactose and milk sodium were measured to assess mammary TJ leakiness. Principal factor analysis (PFA) showed that the first two principal factors (PFs) contributed with 44.47% and 20.57% of the total variance in the experiment and, as feeding levels increased, milk stability to the ethanol test became higher and plasma lactose levels decreased, which indicates lower permeability of the mammary gland cell TJ. Correspondence analyses were consistent with PFA and also showed that lower feeding levels were related to reduced milk stability, high plasma lactose, high sodium in milk, low milk lactose (another parameter used to assess TJ permeability) and higher cortisol levels, indicating the stress to which animals were submitted. All observations were grouped in three clusters, with some of the above-mentioned patterns. Feeding restriction was associated with higher permeability of TJ, decreasing milk stability to the ethanol test.     

狂犬病病毒抗体胶体金检测试纸的制备

通过胶体金免疫层析技术建立一种特异、便捷、快速的狂犬病病毒抗体检测方法,对犬等动物免疫狂犬病疫苗后的抗体水平监测提供参考。用醋酸锌沉淀法沉淀狂犬病病毒CVS11,Sepharose 4FF进行层析纯化。用柠檬酸三钠还原法制备的胶体金,标记纯化的狂犬病病毒,喷于试纸的结合释放垫 (金标垫),将SPA (葡萄球菌表面A蛋白) 和纯化的兔抗狂犬病病毒IgG分别喷于试纸的T (检测线) 处和C (对照线) 处,组装试纸条。用制备的试纸条对261份犬血清进行检测,与快速荧光灶抑制试验 (RFFIT) 检测的结果一致;对已知效价的犬狂犬病毒中和抗体 (VNA) 大于0.5 IU,结果为阳性;对狂犬病病毒中和抗体 (VNA) 小于0.5 IU/mL的血清,结果为阴性。制备的狂犬病病毒抗体胶体金检测试纸检测犬血清抗体,具有特异、便捷、快速的特点,能够检测出狂犬病病毒中和抗体大于0.5 IU的血清,适用于临床犬血清抗体水平监测,具有良好的应用前景。     

Exploration of lagged relationships between mastitis and milk yield in dairycows using a Bayesian structural equation Gaussian-threshold model

A Gaussian-threshold model is described under the general framework of structural equation models for inferring simultaneous and recursive relationships between binary and Gaussian characters, and estimating genetic parameters. Relationships between clinical mastitis (CM) and test-day milk yield (MY) in first-lactation Norwegian Red cows were examined using a recursive Gaussian-threshold model. For comparison, the data were also analyzed using a standard Gaussian-threshold, a multivariate linear model, and a recursive multivariate linear model. The first 180 days of lactation were arbitrarily divided into three periods of equal length, in order to investigate how these relationships evolve in the course of lactation. The recursive model showed negative within-period effects from (liability to) CM to test-day MY in all three lactation periods, and positive between-period effects from test-day MY to (liability to) CM in the following period. Estimates of recursive effects and of genetic parameters were time-dependent. The results suggested unfavorable effects of production on liability to mastitis, and dynamic relationships between mastitis and test-dayMYin the course of lactation. Fitting recursive effects had little influence on the estimation of genetic parameters. However, some differences were found in the estimates of heritability, genetic, and residual correlations, using different types of models (Gaussian-threshold vs. multivariate linear).     

Genotype by environment interaction due to heat stress during gestation and postpartum for milk production of Holstein cattle

Remarkable increases in the production of dairy animals have negatively impacted their tolerance to heat stress (HS). The evaluation of the effect of HS on milk yield is based on the direct impact of HS on performance. However, in practical terms, HS also exerts its influence during gestation (indirect effect). The main purpose of this study was to identify and characterize the genotype by environment interaction (G × E) due to HS during the last 60 days of gestation (THI_g) and also the HS postpartum (THI_m) over first lactation milk production of Brazilian Holstein cattle. A total of 389 127 test day milk yield (TD) records from 1572 first lactation Holstein cows born in Brazil (daughters of 1248 dams and 70 sires) and the corresponding temperature–humidity index (THI) obtained between December 2007 and January 2013 were analyzed using different random regression models. Cows in the cold environment (THI_g = 64 to 73) during the last 60 days of gestation produced more milk than those cows in a hot environment (THI_g = 74 to 84), particularly during the first 150 days of lactation (DIM). The heritabilities (h²) of TD were similar throughout DIM for cows in THI_g hot (0.11 to 0.20) or (0.10 to 0.22), while the genetic correlations (r_g) for TD between these two environments ranged from 0.11 to 0.52 along the first 250 DIM. The h² estimates for TD across THI_m were similar for cows in THI_g hot (0.07 to 0.25) and THI_g cold (0.08 to 0.19). The r_g estimates ranged from 0.17 to 0.42 along THI_m between TD of cows in cold and hot THI_g. The results were consistent in demonstrating the existence of an additional source of G × E for TD due to THI_g and THI_m. The present study is probably the first to provide evidence of this source of G × E; further research is needed because of its importance when the breeding objective is to select animals that are more tolerant to HS.     

Determining the source of Bacillus cereus and Bacillus licheniformis isolated from raw milk, pasteurized milk and yoghurt

Aims:  Strain-specific detection of Bacillus cereus and Bacillus licheniformi s in raw and pasteurized milk, and yoghurt during processing.
Methods and Results:  Randomly selected isolates of Bacillus spp. were subjected to PCR analysis, where single primer targeting to the repetitive sequence Box elements was used to fingerprint the species. The isolates were separated into six different fingerprint patterns. The results show that isolates clustered together at about the 57% similarity level with two main groups at the 82% and 83% similarity levels, respectively. Contamination with identical strains both of B. cereus and B . licheniformis in raw and pasteurized milk was found as well as contaminated with different strains (in the case of raw milk and yoghurt/pasteurized milk and yoghurt). Several BOX types traced in processed milk samples were not discovered in the original raw milk.
Conclusions:  BOX-PCR fingerprinting is useful for characterizing Bacillus populations in a dairy environment. It can be used to confirm environmental contamination, eventually clonal transfer of Bacillus strains during the technological processing of milk.
Significance and Impact of the Study:  Despite the limited number of strains analysed, the two Bacillus species yielded adequately detectable banding profiles, permitting differentiation of bacteria at the strain level and showing their diversity throughout dairy processing.     

Growth of bifidobacteria and clostridia on human and cow milk saccharides

For healthy infants, which were born normally and fully breastfed, the dominant component of the intestinal microflora are bifidobacteria. However, infants born by caesarean section possess clostridia as a dominant intestinal bacterial group. The aim of the present study was to determine whether bifidobacteria and clostridia are able to grow on human milk oligosaccharides (HMOs) and other carbon sources - lactose, cow milk (CM) and human milk (HM). Both bifidobacteria and clostridia grew on lactose and in CM. Bifidobacteria grew in HM and on HMOs. In contrast, 3 out of 5 strains of clostridia were not able to grow in HM. No clostridial strain was able to utilise HMOs. While both bifidobacterial strains were resistant to lysozyme, 4 out of 5 strains of clostridia were lysozyme-susceptible. It seems that HMOs together with lysozyme may act as prebiotic-bifidogenic compounds inhibiting intestinal clostridia.     

鲤疱疹病毒Ⅱ型抗体胶体金检测试纸条的制备和分析

【背景】由鲤疱疹病毒Ⅱ型(cyprinid herpesvirus-2, CyHV-2)引起的疱疹病毒性造血坏死病在鲫和金鱼中的暴发给水产养殖业造成了巨大的经济损失。【目的】开发一种快速、现场检测鲫是否感染过CyHV-2和监测鲫CyHV-2IgM抗体水平的胶体金检测试纸条。【方法】将CyHV-2与胶体金结合作为金标抗原、Protein A作为检测线、兔源rORF66多克隆抗体进行划线作为质控线,分析胶体金试纸条最佳制备及组装条件,确定胶体金标记最适pH、金标抗原最适浓度,以及检测线(test line, T线)、质控线(control line, C线)最适划线浓度等。【结果】本研究制备的CyHV-2抗体胶体金试纸条可以使用全血测试,与常见的其他鱼类抗体血清无交叉反应,如草鱼呼肠孤病毒抗体阳性血清、鳜虹彩病毒抗体阳性血清等。试纸条最低限度可以检测到1:100稀释的阳性血清抗体,由试纸条检测线的深浅可以初步判断鱼体中抗体水平。试纸条通过对10条鲫鱼血清样品检测并和金鱼造血器官坏死病毒检测方法(GB/T 36194—2018)进行Kappa分析,Kappa值为0.80,表明二者有较高的符合...     

Carbohydrate phenotyping of human and animal milk glycoproteins

Breast-milk has a well-known anti-microbial effect, which is in part due to the many different carbohydrate structures expressed. This renders it a position as a potential therapeutic for treatment of infection by different pathogens, thus avoiding the drawbacks of many antibiotics. The plethora of carbohydrate epitopes in breast-milk is known to differ between species, with human milk expressing the most complex one. We have investigated the expression of protein-bound carbohydrate epitopes in milk from man, cow, goat, sheep, pig, horse, dromedary and rabbit. Proteins were separated by SDS-PAGE and the presence of carbohydrate epitopes on milk proteins were analysed by Western blotting using different lectins and carbohydrate-specific antibodies. We show that ABH, Lewis (Le)^x, sialyl-Le^x, Le^a, sialyl-Le^a and Le^b carbohydrate epitopes are expressed mainly on man, pig and horse milk proteins. The blood group precursor structure H type 1 is expressed in all species investigated, while only pig, dromedary and rabbit milk proteins carry H type 2 epitopes. These epitopes are receptors for Helicobacter pylori (Le^b and sialyl-Le^x), enteropathogenic (H type 1, Le^a and Le^x) and enterotoxic Escherichia coli (heat-stable toxin; H type 1 and 2), and Campylobacter jejuni (H type 2). Thus, milk from these animals or their genetically modified descendants could have a therapeutic effect by inhibiting pathogen colonization and infection. Published in 2005.     

Cumulative exposure and dietary risk assessment of phthalates in bottled water and bovine milk samples: A preliminary case study in Tamil Nadu,India

Exposure to phthalates may cause adverse health effects in wildlife and humans. Study on phthalates exposure and risk is limited in the Indian context. Therefore, this preliminary investigation was performed to ascertain the phthalates exposure through bottled water and milk among the Indian sub-population. Phthalates were extracted from water and milk by solid-phase and ultrasonication methods, respectively, and analysis was performed using gas chromatography–mass spectrometry. Total phthalates in bottled water and milk were in the range of 39–7820 ng/L and 56–686 ng/g, respectively, with the highest contribution from diethylhexyl phthalate (DEHP). A substantial increase in phthalates concentration in bottled water was observed with increased shelf life. Total mean phthalates in packed milk (245 ng/g) and raw milk (134 ng/g) shows potential enrichment during “farm to table” process. Among phthalates, the lowest risk was expected from diethyl phthalate, whereas the highest risk was observed for DEHP with cumulative dietary exposure of 0.23 μg/kg bw/day (median). The human health risk based on tolerable daily intake and reference dose was found safe. This is the first study reporting phthalates migration in packed commodities from a developing country, India, which further warrants extensive phthalates exposure assessment to understand its effect on public health.     

Regulation of soy isoflavones on weight gain and fat percentage: evaluation in a Chinese Guangxi minipig model

This study was conducted to determine the effects of soy isoflavones on changes in body and tissue weight and on insulin-like factor I (IGF-I) and peroxisome proliferator-activated receptor-γ (PPARγ) gene and protein expression in muscle and adipose tissues in Chinese Guangxi minipig, as a model for studying human nutrition. A total of 72 male Chinese Guangxi minipigs were fed basal diet (control, Con), low dose of soy isoflavones and high dose of soy isoflavones (HSI). The results showed that HSI increased the body weight (BW) gain and fat percentage of minipigs (P < 0.05). In addition, the serum concentrations of IGF-I and interleukin-6 were increased by high levels of soy isoflavones (P < 0.05). Furthermore, a diet containing soy isoflavones enhanced IGF-I mRNA expression levels in longissimus muscle, but decreased these levels in perirenal fat. However, the mRNA and protein expression levels of PPARγ in longissimus muscle and subcutaneous adipose tissue were both increased when compared with the Con. The data indicated that soy isoflavones regulated the BW gain and fat percentage of Chinese Guangxi minipigs, which also showed changes in IGF-I system and PPARγ. However, further research is required to clarify the causative relationship.     

Safety of milk and milk derivatives in relation to BSE: the lactoferrin example

Bovine Spongiform Encephalopathy (BSE) belongs to Transmissible Spongiform Encephalopathies (TSEs) or Prion diseases. BSE is a feed borne infection of cattle. Epidemiological and laboratory data suggest that the BSE infectious agent is responsible for the variant form of Creutzfeldt-Jakob Disease (vCJD) and that the oral route is the most plausible way of infection. Therefore there is concern that the BSE agent can be transmitted to humans by biological materials (i.e. meat products, blood, milk) from susceptible BSE animal species (mostly cows but possibly, sheep and goats). Lactoferrin (LF) can be produced by purification from large volumes of cow's milk or whey. Therefore, a potential BSE risk for milk and milk products needs to be evaluated by risk assessment. The Committee for proprietary Medicinal Products--CPMP of the European Commission and the WHO have categorized risk tissues from TSE susceptible ruminant species in different classes in relation to the BSE risk for medicinal products. Milk, colostrum, and tissues of the mammary gland have been classified in the category of no detectable infectivity. A secondary contamination of milk can be virtually excluded (i.e. milk is taken from living animals). In the light of current scientific knowledge and irrespective of the geographical origin, milk and milk derivatives (e.g. lactoferrin, lactose) are unlikely to present any risk of TSE contamination provided that milk is sourced from healthy animals in the same conditions as milk collected from human consumption. So the risk of milk and milk derivatives in relation to BSE is negligible.     

Composition and stability of the vervet monkey milk microbiome

The human milk microbiome is vertically transmitted to offspring during the postnatal period and has emerged as a critical driver of infant immune and metabolic development. Despite this importance in humans, the milk microbiome of nonhuman primates remains largely unexplored. This dearth of comparative work precludes our ability to understand how species‐specific differences in the milk microbiome may differentially drive maternal effects and limits how translational models can be used to understand the role of vertically transmitted milk microbes in human development. Here, we present the first culture‐independent data on the milk microbiome of a nonhuman primate. We collected milk and matched fecal microbiome samples at early and late lactation from a cohort of captive lactating vervet monkeys (N = 15). We found that, similar to humans, the vervet monkey milk microbiome comprises a shared community of taxa that are universally present across individuals. However, unlike in humans, this shared community is dominated by the genera Lactobacillus, Bacteroides, and Prevotella. We also found that, in contrast to previous culture‐dependent studies in humans, the vervet milk microbiome exhibits greater alpha‐diversity than the gut microbiome across lactation. Finally, we did not find support for the translocation of microbes from the gut to the mammary gland within females (i.e., “entero‐mammary pathway”). Taken together, our results show that the vervet monkey milk microbiome is taxonomically diverse, distinct from the gut microbiome, and largely stable. These findings demonstrate that the milk microbiome is a unique substrate that may selectively favor the establishment and persistence of particular microbes across lactation and highlights the need for future experimental studies on the origin of microbes in milk.