Silver nanoparticles as a potential antimicrobial additive for weaned pigs

Three experiments were carried out in order to determine the potential of silver nanoparticles as an additive in diets for weanling pigs. In Experiment 1, ileal contents of 4 pigs weaned 7 days before were incubated in vitro for 4 h at 37 °C with 0, 25, 50 and 100 μg Ag/g. Metallic silver (in colloidal form) linearly reduced coliforms (P=0.003) and lactobacilli (P=0.041) concentration, but did not affect the lactobacilli proportion compared with the control. In Experiment 2, three groups of 5 weaned pigs were given a diet with 0, 20 or 40 mg Ag/kg. The second week after weaning daily growth of pigs increased linearly (P=0.007) with the dose of silver nanoparticles. A trend (P=0.073) for a linear reduction in the ileal concentration of coliforms was observed by culture counts, but lactobacilli remained unaffected. There were no differences among treatments in the ileal concentration of coliforms or lactobacilli measured by FISH. However, the concentration of total bacteria (P=0.010) and Atopobium (P=0.001) decreased at a decreasing rate. No differences were detected in the other bacterial groups tested, except for a lowest concentration of the Clostridium perfringens/Clostridium histolyticum group in 20 mg Ag/kg (P=0.012). No treatment effect was detected in histological examination of ileal mucosa. In Experiment 3, productive performance and silver retention in tissues with 0, 20 or 40 mg Ag/kg diet were studied with 6 lots of 4 piglets per treatment in five weeks after weaning. Feed intake was highest in treatment with 20 mg Ag/kg (P<0.05). No effect was observed on apparent digestibility coefficients. After 5 weeks, there was no silver retention in skeletal muscles or kidneys, but it was observed, although in minimal proportions, in liver (1.354 and 2.445 μg Ag/g dry liver for 20 and 40 mg Ag/kg). The potential effect of metallic silver as a dietary additive on intake and growth of weaned piglets could be mediated through its antimicrobial properties, either against certain bacterial groups or reducing the microbial load of the small intestine; however, other beneficial effects over the host metabolism cannot be discarded.     

Antioxidant and food additive BHA prevents TNF cytotoxicity by acting as a direct RIPK1 inhibitor

Butylate hydroxyanisole (BHA) is a synthetic phenol that is widely utilized as a preservative by the food and cosmetic industries. The antioxidant properties of BHA are also frequently used by scientists to claim the implication of reactive oxygen species (ROS) in various cellular processes, including cell death. We report on the surprising finding that BHA functions as a direct inhibitor of RIPK1, a major signaling hub downstream of several immune receptors. Our in silico analysis predicts binding of 3-BHA, but not 2-BHA, to RIPK1 in an inactive DLG-out/Glu-out conformation, similar to the binding of the type III inhibitor Nec-1s to RIPK1. This predicted superior inhibitory capacity of 3-BHA over 2-BHA was confirmed in cells and using in vitro kinase assays. We demonstrate that the reported protective effect of BHA against tumor necrosis factor (TNF)-induced necroptotic death does not originate from ROS scavenging but instead from direct RIPK1 enzymatic inhibition, a finding that most probably extends to other reported effects of BHA. Accordingly, we show that BHA not only protects cells against RIPK1-mediated necroptosis but also against RIPK1 kinase-dependent apoptosis. We found that BHA treatment completely inhibits basal and induced RIPK1 enzymatic activity in cells, monitored at the level of TNFR1 complex I under apoptotic conditions or in the cytosol under necroptosis. Finally, we show that oral administration of BHA protects mice from RIPK1 kinase-dependent lethality caused by TNF injection, a model of systemic inflammatory response syndrome. In conclusion, our results demonstrate that BHA can no longer be used as a strict antioxidant and that new functions of RIPK1 may emerge from previously reported effects of BHA.Subject terms: Kinases, Apoptosis, Necroptosis, Target identification, Cell death and immune response     

DNA binding studies of tartrazine food additive

The interaction of native calf thymus DNA with tartrazine in 10?mM Tris-HCl aqueous solution at neutral pH 7.4 was investigated. Tartrazine is a nitrous derivative and may cause allergic reactions, with a potential of toxicological risk. Also, tartrazine induces oxidative stress and DNA damage. Its DNA binding properties were studied by UV-vis and circular dichroism spectra, competitive binding with Hoechst 33258, and viscosity measurements. Tartrazine molecules bind to DNA via groove mode as illustrated by hyperchromism in the UV absorption band of tartrazine, decrease in Hoechst-DNA solution fluorescence, unchanged viscosity of DNA, and conformational changes such as conversion from B-like to C-like in the circular dichroism spectra of DNA. The binding constants (K(b)) of DNA with tartrazine were calculated at different temperatures. Enthalpy and entropy changes were calculated to be +37 and +213 kJ mol(-1), respectively, according to the Van't Hoff equation, which indicated that the reaction is predominantly entropically driven. Also, tartrazine does not cleave plasmid DNA. Tartrazine interacts with calf thymus DNA via a groove interaction mode with an intrinsic binding constant of 3.75?×?10(4) M(-1).     

Characterization of Kluyveromyces marxianus as a potential feed additive for ruminants

Aim: The aim of this study was to find suitable yeast isolates as potential microbial feed additives for ruminants. Methods and Results: Yeast isolates from traditional fermented food (tapai) and home‐made wine were selected based on their tolerance to volatile fatty acids (VFA) mixture of acetic, propionic and butyric acids and to pH and temperature according to the rumen condition. The ability to grow in and produce ethanol was determined in yeast extract peptone glucose broth supplemented with a VFA mixture (VFA‐YEPG medium). Fifty‐five isolates showed OD_660nm values between 0·35–0·6, and 27 isolates showed ethanol production in the range of 0·17–0·30% (v/v). All selected isolates were identified as Kluyveromyces marxianus base on biochemical tests (BioLog kit; Biolog Inc., Hayward, CA) and molecular techniques. The best isolate in terms of ethanol production (K. marxianus WJ1) significantly (P < 0·01) improved in vitro apparent dry matter (DM) digestibility of alfalfa (Medicago sativa), guinea grass (Panicum maximum) and timothy (Phleum pretense) hay by rumen microbes. Conclusion: Yeast isolates from tapai and wine were able to grow in VFA‐YEPG medium, and K. marxianus WJ1 improved in vitro DM digestibility of plant substrates. Significance and Impact of the Study: This study indicated the possibility of using K. marxianus as a microbial feed additive.     

Cationic-modified PVA as a dry strength additive for rice straw fibers

Extensive research has shown that non-wood fibers are able to be substituted for wood fibers. The major shortcoming of non-fibers is their high silica content that causes some operational problems in mills, and hence silica should be kept in pulps. By keeping silica in pulps, however, the mechanical properties of papers are reduced, and a dry strength additive may be required. In this study, cationic polyvinyl alcohols (C-PVA) with two different molecular weights were prepared, and employed as dry strength additives. The adsorption of polymers on rice straw fibers obtained via soda-air-anthraquinone (AQ) pulping under various conditions was investigated thoroughly. Convincing results demonstrated that high molecular weight polymers performed more efficiently on dry strength enhancements of papers, while they adsorbed less than lower molecular weight polymers on fibers. However, the stiffness of fibers was increased to a larger extent by applying a higher molecular weight C-PVA.     

Exudates as a fallback food for Callimico goeldii

Fallback foods have been defined as resources for which a species has evolved specific masticatory and digestive adaptations, and are consumed principally when preferred foods are scarce. In the present field investigation, we examine fungi, fruit, and exudate consumption in one group of Callimico goeldii in order to determine the importance of exudates as a fallback food for this species. Based on a total of 1,198 hr of quantitative behavioral data collected between mid-November 2002-August 2003, we found that pod exudates of Parkia velutina accounted for 19% of callimico feeding time in the dry season. This resource was not consumed in the wet season when fruits and fungi were the most common items in the diet. In the dry season of 2005 (July), the same callimico study group did not consume Parkia pod exudates. Instead, the group ate exudates obtained from holes gouged in tree trunks by pygmy marmosets and exudates resulting from natural weathering and insect damage on trunks, roots, and lianas. Pod exudates are reported to contain greater amounts of readily available energy than do trunk and root exudates, and were consumed throughout all periods of the day, particularly in the late afternoon. Trunk and root exudates were consumed principally in the morning. We propose that digestive adaptations of the hindgut, which enable callimicos to exploit fungi (a resource high in structural carbohydrates) year-round, predispose them to efficiently exploit and process exudates as fallback foods when other resources, such as ripe fruits, are scarce.     

Utility of subtilisin GX as a detergent additive

Subtilisin GX, purified from alkalophilic Bacillus sp. GX6644 (ATCC 53441), was assessed for its ability to augment detergencies of commercial laundry products. The addition of the alkaline protease to detergent compositions resulted in significant increases in the removal of proteinaceous stains from a standard soiled fabric during Tergotometer wash tests. The enzyme was effective in liquid and powdered detergent formulations and functional over a wide pH and temperature range. The results indicate that the alkaline protease from Bacillus sp. GX6644 possesses properties suitable as a detergent additive.     

Campylobacter jejuni as a secondary colonizer of poultry biofilms

Aims: The objective of this study was to determine if survival of culturable Campylobacter jejuni outside the host was increased by entrapment in pre-established biofilms. Methods and Results: Campylobacter jejuni was inoculated into four biofilm populations isolated from poultry environments and cultured at three temperatures. Survival of culturable Camp. jejuni in some pre-established biofilms was extended vs survival of culturable Camp. jejuni in broth. But some biofilms were detrimental to survival of culturable Camp. jejuni. Denaturing gradient gel electrophoresis analysis indicated differences in bacterial profiles depending on initial source and temperature of culturing, which may have had impacts on survival of culturable Camp. jejuni. Further investigation showed no evidence of interspecies cell signalling indicating that secondary colonization was only physical. Conclusions: The results of this study show Camp. jejuni’s attachment to surfaces is facilitated by pre-established biofilms and survival of culturable Camp. jejuni may be extended in some pre-established biofilms, but these biofilms do not fully explain long-term survival of culturable Camp. jejuni outside hosts. Significance and Impact of the Study: This study provides new information concerning survival of culturable Camp. jejuni outside the host and shows biofilms may be important in transmission and prevalence of Camp. jejuni.     

Selection of Saccharomyces cerevisiae strains for use as a microbial feed additive

Saccharomyces cerevisiae ITCCF 2094, NCIM 3052, 1031, 1032, NCDC 42, 45, 47, 49 and 50 were screened for their tolerance to pH 2.0-7.0, various concentrations (0.00, 0.10, 0.25 0.50 and 1.0%) of a mixture of acetic, propionic and butyric acids (70:20:10), and bile salts (0.00, 0.30, 0.60 and 0.90%). Low pH (2.0-4.0) and addition of organic acids or bile salts in the medium inhibited the growth of all the strains tested, but the percentage of inhibition was variable in the different strains of yeast. Two of the strains showing maximum tolerance, 42 and 49, were further tested for in vitro dry matter degradability (IVDMD) using green berseem, wheat straw and oat hay as substrates. Saccharomyces cerevisiae 49 enhanced the IVDMD of berseem and wheat straw whereas S. cerevisiae 42 was ineffective. Based on the results of the present experiment, S. cerevisiae NCDC 49 can be considered as the best strain which might tolerate the adverse conditions in the gastrointestinal tract when used as a live microbial feed supplement in the diet of the animals.     

Reptiles as a food resource

Reptiles have served as an important source of protein for human populations around the world. Exploitation for food is heaviest in the tropical and sub-tropical regions, but also occurs in temperate areas. Of all reptiles, turtles are the most heavily exploited for human consumption. High, unsustainable levels of exploitation for food are directly responsible for the precarious conservation status of many turtles. Crocodilians, snakes, and lizards may be locally important food sources, however, with the exception of a few lizard species, they are exploited in a less intense and generally non-commercial manner for human consumption. In comparison, the commercial skin trade poses a far greater threat to the survival of crocodilians as well as certain large snakes and lizards. Recent field reports have implicated the south east Asian medicinal trade as a growing threat to reptiles, especially turtles and snakes. There are few unequivocal examples of managed harvest programmes for reptiles that are economically and culturally viable, as well as biologically sustainable. Given the economic importance of reptiles as sources of protein and other highly valued commodities, it is imperative that more attention be focused on the development of sustainable use programmes for these species.     

A biotechnological process for treatment and recycling poultry feathers as a feed ingredient

A strain of Kocuria rosea with keratinolytic capacity was cultured aerobically on submerged feathers to obtain a fermented feather meal (FFM). This FFM enriched with cells of K. rosea mainly contains crude protein (71%). The pepsin digestibility of the fermented product (88%) was similar to the value of the commercial feather meal and more than 70% greater that untreated feathers. The bacterial biomass improved the content of amino acids lysine (3.46%), histidine (0.94%) and methionine (0.69%). Additionally, the amino acid availability tested by in vivo assay was greater than commercial feather meal. The microbial cells also supplied carotenoid pigments to FFM (68 ppm). These results suggest that feather meal enriched with K. rosea may be useful in animal feeding as protein and pigment source.     

Aphid galls as a double food source for woodpeckers

An adult female and a young great spotted woodpecker Dendrocopos major were found exploiting galls of the elm balloon‐gall aphid Eriosoma lanuginosum by eating both the insects and their honeydew. Literature offers sparse and indirect information to explain this behavior. Taking both aphids and honeydew from within galls is reported here for the first time for a bird species. Only one other vertebrate, the Eurasian red squirrel Sciurus vulgaris, would show similar behavior. In contrast with the seeming rarity of such a feeding way, likely advantages in the double food source suggest it may have been overlooked.     

Olaquindox as performance-promoting feed additive for growing pigs

Olaquindox (trade name: Bay-o-nox, Bayer Co.) is a quinoxalin derivative (C₁₂H₁₃N₃O₄). Its efficacy was tested with particular reference to diets with and without a copper supplement. Olaquindox was included in the diet of pigs up to 54 kg liveweight, but performance was monitored between 18 and 87 kg. The daily gain and feed: gain ratio were significantly improved by supplementing the diet with Olaquindox. The response to copper was not significant. Carcass quality was not affected.     

The soil fauna as a food source for moles

Moles feed mainly on insects and earthworms and may eat 18 to 36 k (40 to 80 lb) per annum, collected in an area of about 1/25 hectare (1/10 acre). This largely restricts them to deciduous woodland and old grassland on "mull" soils since field populations of soilinsects cannot provide them with enough food but earthworm populations can. Slugs and millipedes may be relatively unpalatable.
Caches of earthworms stored by moles consist almost entirely of Lumbricus terrestris immobilized by removal or multilation of the anterior 3–5 segments. It is still uncertainhow and when the caches are made. Earthworm cocoons are prominent in the diet of moles in pastures but how they are located is not yet known.