Performance of Green Microalgae-Activated Sludge and Diatom-Activated Sludge Co-Cultures in Kitchen Wastewater Treatment: Nutrient Removal Efficiency and Cellular Fatty Acid Profiling

Comparison of Yersinia pestis to other closely related Yersinia species using fatty acid profiles

Capillary gas chromatography with flame ionization detection (GC-FID) was used to determine the cellular fatty acid (CFA) profiles of 134 Enterobacter sakazakii strains, and these were compared to the CFA profiles of other closely related Enterobacter and Citrobacter species. For GC-FID analysis, whole cell fatty acid methyl esters (FAMEs) from cells cultured on brain heart infusion (BHI) agar at 37 degrees C for 24 h were obtained by saponification, methylation, and extraction into hexane/methyl tert-butyl ether. A database for E. sakazakii was prepared using fatty acid profiles from the 134 strains. Major fatty acids of E. sakazakii strains evaluated in this study were straight-chain 12:0, 14:0, and 16:0, unsaturated 18:1 omega7c, and 17:0 omegacyclo 7-8. Principal component analysis (PCA) based on CFA profiles for E. sakazakii strains shows separation of E. sakazakii subgroups A and B. The CFA profiles for E. sakazakii and Enterobacter cloacae show that there are several fatty acids, 14:0, 17:0 omegacyclo 7-8, 18:1 omega7c, and summed 16:1 omega6c/16:1 omega7c, that differ significantly between these two species. A PCA model based on CFA profiles for E. sakazakii strains clearly shows separation of E. sakazakii from closely related Enterobacter and Citrobacter species. Analysis of FAMEs from E. sakazakii strains grown on BHI agar by a rapid GC-FID method can provide a sensitive procedure for the identification of this organism, and this analytical method provides a confirmatory procedure for the differentiation of E. sakazakii strains from closely related Enterobacter and Citrobacter species.

The number of male calves from the Irish dairy herd has increased following the abolition of EU milk quotas in 2015. This is a new resource for the industry, and they can be reared economically to produce meat of acceptable eating quality with optimal fatty acid (FA) profile. The effects of breed and feeding treatment on the FA profile of the longissimus thoracis (LT) muscles of young dairy bulls (n = 69) of Holstein–Friesian and Jersey × Holstein–Friesian were evaluated. The relationship between FA composition and sensory characteristics was also investigated. Bulls were offered either 1 or 2 kg of concentrates at pasture during the first grazing season. Bulls finished on silage with 5 kg of concentrates or on ad libitum concentrates were slaughtered at 15 months of age, while bulls slaughtered at 19 months were fed either ad libitum pasture or pasture with 5 kg of concentrates during a second grazing season and finished on pasture with 5 kg of concentrates or ad libitum concentrates. Pasture-finished 19-month-old bulls had higher relative proportions of C18:0 (P < 0.001), C20:5n3 (eicosapentaenoic acid; P < 0.001), C18:2n6c (P < 0.05), C20:4n6 (P < 0.01), and total n-3 (P < 0.001) and n-6 polyunsaturated FAs (P < 0.05), but reduced C14:0, C16:0, C14:1, C16:1 and total monounsaturated FA (P < 0.001) proportions than in other production treatments. The silage-based finishing system of 15-month-old bulls increased the relative proportions of C15:0 (P < 0.01), C18:0 (P < 0.001) and total saturated FA (P < 0.01), but decreased the proportions of C20:3n6 (P < 0.05) and total unsaturated FA (P < 0.01) compared with the ad libitum-concentrate finishing system. However, the feeding system of the first or second grazing seasons had limited effects on the FA profile. Jersey × Holstein–Friesian breed type had higher relative proportions of C14:1 and C16:1 (P < 0.05), but lower C15:0 (P < 0.01), C17:0 (P < 0.001) and C17:1 (P < 0.01) proportions than did Holstein–Friesian beef. Slaughter age did not affect the FA profile. Monounsaturated FA, C14:0 and C16:0 proportions were positively (P < 0.05) correlated, but polyunsaturated FA proportion was negatively (P < 0.05) correlated with intramuscular fat content, sensory roast beef aroma, flavour, flavour length, juiciness, initial tenderness and ease of disintegration scores. Finishing system and slaughter weight were well discriminated on the basis of FA relative proportions by canonical discriminant analysis.

Context The increased number of male dairy origin calves in Ireland due to the abolition of European Union milk quotas is a potential resource for the beef industry. Rearing these animals as bulls rather than steers is more efficient from a production perspective. Ensuring satisfactory quality of bull beef from dairy origin is essential. Aim To determine the effect of two production systems and three muscle types on physico-chemical characteristics and fatty acid (FA) profile of beef from Holstein-Friesian (HF) bulls. Methods Thirty HF bulls were equally assigned to two production systems, namely, slaughter at under 16 months of age or slaughter at 19 months of age. Longissimus thoracis (LT), Semitendinosus (ST) and Gluteus medius (GM) muscles were excised post-slaughter for determination of pH, colour, Warner–Bratzler (WB) variables, cook loss, chemical composition [intramuscular fat (IMF), moisture, protein, ash], collagen characteristics and FA profile. Results WB variables and cook loss after 14 days postmortem ageing, and insoluble and total collagen contents were higher, while IMF content, redness and saturation at 24 h post-blooming were lower for muscles from the 19-month production system. Muscles from the under 16-month production system had a higher saturated fatty acid (SFA) proportion and n-6:n-3 polyunsaturated fatty acid (PUFA) ratio, while muscle from the 19-month production system had a higher PUFA proportion, n-3 PUFA proportion and PUFA:SFA ratio. The GM muscle had the lowest L* value, followed by LT and ST. Yellowness, saturation and hue angle were greater in ST. LT had lower WB variables, cook loss, moisture, and a higher IMF content than ST and GM. The PUFA proportion and PUFA:SFA ratio were highest in ST, followed by GM and LT. IMF, total FA, SFA and monounsaturated fatty acid (MUFA) concentrations were higher in LT from the under 16-month production system bulls (the interaction). Conclusions Beef from the under 16-month production system compared with beef from the 19-month production system, and LT compared with ST and GM muscles had better quality characteristics. Implications Dairy bulls can produce beef of acceptable quality. The findings will guide selection of the combination of production system and muscle type most appropriate to specific market requirements.

Compared with maize silage- and concentrate-based diets, herbage-based diets were repeatedly shown to favourably influence the milk fatty acid (FA) profile. However, it is unclear how the herbage feeding mode (grazing vs indoor green-feeding) and conservation (fresh herbage vs hay vs silage) modify the milk FA profile. Therefore, the aim of the present experiment was to investigate the effect of different herbage utilisation methods (including herbage feeding mode and herbage conservation method) on the ruminal biohydrogenation of dietary FA and the consequences on the milk FA composition in cows of two breeds (Holstein and Montbéliarde). Concomitant effects of botanical composition and phenological stage of the herbage on milk FA profile were controlled for by harvesting barn-dried hay and silage simultaneously as first cut from the same ryegrass-dominated grassland in a semi-mountainous region. Seven weeks later, the first regrowth of the same plot was used as fresh herbage, either grazed or fed indoor (indoor green-feeding). Twenty-four Montbéliarde and 24 Holstein cows were randomly allocated to four groups of 12 cows balanced by breed, parity, and milk yield. In a free-stall barn, three groups were given ad libitum access to hay, silage, or fresh herbage, respectively. The fourth group was strip-grazing. All cows were supplemented with 3 kg DM/day of the same energy-rich concentrate. After 2 weeks of adaptation to the forage, samples of forage, concentrate, milk, blood, and rumen fluid were collected. Fatty acid composition of forages, rumen fluid, and milk was analysed by gas chromatography. Haymaking reduced total FA content of the herbage, in particular that of linoleic acid (LA) and α-linolenic acid (ALA). Still, rumen fluid lipids of hay-fed cows had the highest proportion of rumenic acid, LA, ALA, and total polyunsaturated fatty acids (PUFAs). Milk fat from hay-fed cows had the highest proportion of LA, and the apparent transfer rates from feed to milk of LA and ALA were higher in hay-fed cows than in silage-fed cows. The proportion of PUFAs was highest in milk fat from grazing and indoor green-fed Montbéliarde cows and lowest in silage-fed cows of both breeds. In conclusion, the herbage utilisation method affects the ruminal biohydrogenation of LA and ALA, whereby herbage drying particularly increases their transfer from herbage to milk.

The objective of this study was to examine the performance of mixed microalgal bioreactors in treating three different types of wastewaters-kitchen wastewater (KWW), palm oil mill effluent (POME), and pharmaceutical wastewater (PWW) in semi-continuous mode and to analyze the lipid content in the harvested algal biomass. The reactors were monitored for total nitrogen and phosphate removal at eight solid retention times (SRTs): 2, 4, 6, 8, 10, 12, 14, and 16 days. The nutrient uptake kinetic parameters were quantified using linearized Michaelis-Menten and Monod models at steady-state conditions. The nutrient removal efficiency and lipid production were found to be higher in KWW when compared with the other wastewaters. Saturated fatty acids (C16:0, C18:0, and C18:1) accounted for more than 60% of the algal fatty acids for all the wastewaters. The lipid is, therefore, considered suitable for synthesizing biodiesel.

Capillary gas chromatography with flame ionization detection (GC‐FID) analysis of chemical components of bacterial cells has provided useful information for rapid detection and identification of bacteria in clinical and diagnostic bacteriology laboratories and currently has increased significance for both food safety and security. GC‐FID was used to determine the cellular fatty acid (CFA) profiles of closely related Yersinia species. For GC‐FID analysis, whole cell fatty acid methyl esters (FAMEs) from cells cultured on brain heart infusion (BHI) agar at 35 (C for 24 h were obtained by saponification, methylation and extraction into hexane/methyl tert‐butyl ether. A data set for each Yersinia species was prepared using fatty acid profiles from five replicates prepared on different days. Major fatty acids of the 26 Yersinia strains evaluated in this study were straight‐chain 12:0, 14:0, 15:0, 16:0 and unsaturated 16:1 ω7c/16:1 ω6c, 18:1 ω7c, and 14:0 3OH/16:1 iso, and 17:0 ωcyclo 7‐8. The Yersinia species Y. enterocolitica, Y. pseudotuberculosis, Y. frederiksenii, Y. intermedii, Y. kristensenii, and Y. pestis have unique fatty acid patterns. The CFA profiles for Y. pestis and Y. pseudotuberculosis are similar, but there are several fatty acids, 16:1 ω5c, 16:0, 17:1 ω7c, 17:0 ωcyclo 7‐8, 19:0 and summed 18:2 ω6c, 9c/18:0 ante that differ significantly between these two species. Analysis of FAMEs from Yersinia strains grown on BHI agar by a rapid GC‐FID method can provide a sensitive procedure for the identification of these organisms, and this analytical method provides a procedure applicable to issues of both food safety and security.

Capillary GC with flame ionization detection (FID) was used to determine the cellular fatty acid (CFA) profiles of six species in the new genus Cronobacter (Enterobacter sakazakii). The six different species are C. sakazakii, C. malonaticus, C. dublinensis, C. muytjensii, C. turicensis, and C. genomospecies. For GC-FID analysis, whole cell fatty acid methyl esters (FAMEs) from cells cultured on brain heart infusion (BHI) agar at 35 degrees C for 24 h were obtained by saponification, methylation, and extraction into hexane-methyl tert-butyl ether. A data set for 57 strains of Cronobacter species was prepared using fatty acid profiles from two or three replicates prepared on different days. Major fatty acids of the Cronobacter strains evaluated in this study were straight-chain C12:0, C14:0, C16:0, and unsaturated C18:1, omega7c, summed C16:1 omega7c/C16:1 omega6c, and summed C14:0 3-OH/iso-C16:1, and C17:0 omega cyclo 7-8. The CFA profiles for the Cronobacter species are similar, but there are several fatty acids-C12:0, C14:0, C16:0, C18:1 omega7c, and summed C16:1 omega7c/ C16:1 omega6c--that differ significantly among these six species. Analysis of FAMEs from Cronobacter strains grown on BHI agar by a rapid GC-FID method is a sensitive procedure for the identification of these organisms, and this analytical method provides a procedure for the differentiation of strains from closely related Cronobacter species.

Pre-regulation coal mining and subsequent acid mine drainage (AMD) have drastically altered stream quality in the Appalachian region of the USA. Streams impaired by AMD often times demonstrate lowered pH, increases in specific conductance, and increase in dissolved metal concentrations. These changes in the chemical environment are reflected in the biotic community with drastic reductions in diversity and biomass. Recently, there has been an increase in applying traditional measures of food quality to understand how the biofilm community is altered by environmental condition and use for stream quality monitoring. The purpose of this study was two-fold: (1) to use fatty acid profiles to distinguish between biofilm communities in AMD impaired and unimpaired streams and (2) to determine the consistency of biofilm fatty acid profiles throughout the summer sampling period. Impaired streams showed significantly lower pH and increased specific conductance. Biofilm samples from the AMD impaired streams had lower fatty acid content with a decreased proportion of polyunsaturated fatty acids. Fatty acid profiles easily and rapidly separated biofilm communities into their respective categories, either as being impaired by AMD or unimpaired by AMD, using multivariate statistical approaches. Fatty acid profiles were similar within stream type throughout the summer sampling season, and the profiles were correlated to pH and specific conductance. The results of this study suggest that fatty acid profiles can rapidly and accurately categorize the biofilm community responses to environmental impairment.

Simple SummaryUntil now, only a limited number of studies have addressed the influence of combining grazing with total mixed rations (TMRs), in Jersey cows, on milk biocomponents and antioxidant capacity. Thus, the main objective of this study was to compare fatty acid (FA) profiles and antioxidant capacity in milk yielded by cows fed either using a TMR or a partial mixed ration (pTMR) combining a TMR and grazing. The second objective consisted in evaluating FA profiles and changes in lipophilic antioxidants in milk during the grazing period and related to pasture chemical composition. Although the pTMR feeding system led to a decreased daily milk production, milk quality was improved. By comparison, cows having access to pasture (pTMR group) yielded a milk with a higher fat and protein content, but with lower saturated FAs (SFA) and a higher content of unsaturated FAs considered benefic for human health (vaccenic acid (VA), conjugated linoleic acid (CLA), and omega-3 FA (n-3 FA)). Similarly, lipophilic antioxidant (α-tocopherol, retinol, and β-carotene) content was higher in the pTMR group, resulting in a higher total antioxidant capacity in milk. The grazing period showed a significant influence on milk quality; in the milk from the pTMR group, the highest concentrations of benefic FAs (VA, CLA, and n-3 FA), the highest concentration of fat-soluble antioxidants, and the best antioxidant activity, respectively, were obtained in the first grazing period (May), in accordance with the pasture’s chemical composition.This study was carried out to assess the effect of using pasture combined with total mixed ration (TMR) on milk production and composition, fatty acid (FA) profiles, fat-soluble antioxidant content, and total milk antioxidant capacity (TAC). In addition, the effect of milk pasteurization and storage at 2 °C for 4 days, lipophilic antioxidants and TAC were assessed. Two homogeneous groups of Jersey cows (n = 8) were constituted, which were randomly assigned to one of the two treatments: TMR (without access to pasture), or partial mixed diet (pTMR: grazing 8 h/day + TMR indoors). To establish FA profiles and lipophilic antioxidants’ changes in milk during the grazing period, in case of the pTMR group the experimental period was spilt in three grazing periods: P1 (May), P2 (June), and P3 (June/July). Milk yielded from cows having limited access on pasture (pTMR diet) showed an improved FA profile, with higher concentrations of FAs considered benefic for human health (vaccenic acid (VA), conjugated linoleic acid (CLA), omega-3 FA (n-3 FA)) (p < 0.01) and a lower concentration of FAs with hypercholesterolemiant potential (C12:0, C14:0, and C16:0) (p < 0.05), compared to that of the TMR diet. This change in FA profile was correlated with improved sanogenous lipid indices of milk fat (n-6/n-3 FA atherogenic index and thrombogenic index). Milk yielded during the P1 grazing period had higher concentrations of VA, CLA, and n-3 FA (p < 0.05) and lower concentrations of C14:0 and C16:0 (p < 0.01); it exhibited the best values for the main sanogenous fat lipid indices of fat. Moreover, pTMR milk showed a higher α-tocopherol, retinol, and β-carotene content (p < 0.05), positively correlated with TAC values in milk (P1 ˃ P2 ˃ P3). By comparison, cows fed using the TMR diet yielded a higher quantity of milk (p < 0.05), but a lower fat and protein content (p < 0.01), and also a higher saturated FAs and n-6 FA content (p < 0.05) together with a lower concentration of lipophilic antioxidants in milk. Thermal treatment showed no effect on α-tocopherol and retinol content in milk, but their concentrations decreased during the storage, at the same time a TAC decrease. The results of this study prove the positive effect of using pasture combined with TMR on FA profiles, milk antioxidant content, and antioxidant capacity, with beneficial effects on nutrition and health in humans.

Annual cycle and spatial trends in fatty acid composition of suspended particulate organic matter across the Beaufort Sea shelf

Chemostats were used to study the effects of carbon and nitrogen limitation and specific growth rate on 16S rRNA synthesis and cellular fatty acid (CFA) profiles in four human intestinal bacteria (Bacteroides thetaiotaomicron, Bifidobacterium adolescentis, Clostridium bifermentans and Cl. difficile). Cellular fatty acid synthesis varied with dilution rate and nutrient availability in different species, but these cellular constituents were relatively stable phenotypic characteristics in Bact. thetaiotaomicron, where branched chain and hydroxy CFA were good taxonomic markers. Conversely, CFA in the Gram-positive bacteria varied markedly with changes in growth environment. For example, in chemostats, cyclopropane CFA were only synthesized in Cl. bifermentans and Cl. difficile under N-limited conditions. Similarly, Dimethyl acetal (DMA) fatty acids in Bif. adolescentis were primarily produced during N-limited growth, and this was inversely related to dilution rate. At low growth rates, 16S rRNA concentrations (microg rRNA per ml culture) correlated with viable bacterial counts, but were more closely related to specific growth rate when expressed as a function of cell mass (microg rRNA per mg dry weight bacteria). However, this did not reveal differences in bacterial population size and rRNA concentration in C-limited cultures. Thus, at low dilution rates, C limitation strongly reduced rRNA synthesis in Cl. bifermentans, despite viable cell counts being similar to those in N-limited cultures. These results indicate that, while 16S rRNA is a useful indicator of microbial activity, cell growth rate does not necessarily relate to rRNA concentration under all nutritional conditions. Consequently, bowel habit and diet will affect both CFA and rRNA content in bacteria isolated from intestinal samples, and this should be taken into consideration when interpreting such data measurements.

The seeds of two commonly consumed spices; Monodora myristica (Mm) and Myristica fragrans (Mf) were separately defatted with n-hexane and the resulting oils were analyzed for their physicochemical properties and fatty acids profile with a view to assessing their nutritional potentials. Results revealed that Mm and Mf had respective percentage oil yields of 25% and 37.7%; free fatty acid of 32.52 and 1.71%; saponification values of 240.95 and 230.47 mgKOH/g; iodine values of 89.75 and 97.75 gI2/100g oil;&nbsp; peroxide values of 2.32 and 1.65 MeqKOH/g. Oleic acid (36.35%), linoleic acid (50.27%) and linolenic (1.55%) acids were the major unsaturated fatty acids detected in M. myristica spice oil while palmitic acid (8.78%) and butyric acid (3.74%) were the few saturated fatty acids contained in the oil. In Monodora fragran soil, palmitoleic (1.78%), oleic (14.82%) and linolenic (3.36 %) were the unsaturated fatty acids obtained, while butyric (24.20%), hexanoic (6.74%), lauric (16.71%), myristic (3.40%), palmitic (26.72%) and stearic (2.57%) were the saturated fatty acids detected in the oil. M. myristica contained higher proportion of polyunsaturated fatty acids compared to Monodora fragrans. The high free fatty acids with low iodine value in Mm and high saturated fatty acids in Mf called for caution in their encapsulation in food formulations. &nbsp; Key words: Monodora myristica, Myristica fragrans, fatty acids profile, food formulations.

Capillary gas chromatography (GC) with flame ionization detection was used to determine the cellular fatty acid profiles of various food-borne microbial pathogens and to compare the fatty acid profiles of spores and vegetative cells of the same endospore-forming bacilli. Fifteen bacteria, representing eight genera (Staphylococcus, Listeria, Bacillus, Yersinia, Salmonella, Shigella, Escherichia, and Vibrio) and 11 species were used to compare the extracted fatty acid methyl esters (FAMEs). Endospore-forming bacilli were processed to obtain pure spores and whole cell FAMEs for GC analysis. A data set for each bacterial agent was prepared using fatty acid profiles from five replicates prepared on different days. The results showed that these fatty acid intensity profiles were unique for each of the 11 species and that they could be used as a fingerprint for the organisms. The cellular fatty acid profiles for Bacillus anthracis and Bacillus cereus show that there are two branched chain fatty acids, iso 17:1 omega10c and 17:1 anteiso, which are unique in these species. Iso 17:1 omega10c is present in B. cereus vegetative cells and spores but is not observed in B. anthracis. The 17:1 anteiso fatty acid is present in B. anthracis cells but not in B. cereus cells. Fatty acids 16:0 2OH and 17:0 iso 3OH are present in B. anthracis and B. cereus spores but not in the vegetative cells. In summary, analysis of FAMEs from bacteria and spores can provide a sensitive procedure for the identification of food-borne pathogens.

Dietary fat (virgin olive oil or sunflower oil) and physical training interactions on blood lipids in the rat