Feather Meal Research Articles

Analyzing Indicator Microorganisms, Antibiotic ResistantEscherichia coli, and Regrowth Potential of Foodborne Pathogens in Various Organic Fertilizers

This study analyzed various organic fertilizers for indicator microorganisms, pathogens, and antibiotic-resistant Escherichia coli, and evaluated the growth potential of E. coli O157:H7 and Salmonella in fertilizers. A microbiological survey was conducted on 103 organic fertilizers from across the United States. Moisture content ranged from approximately 1% to 86.4%, and the average pH was 7.77. The total aerobic mesophiles ranged from approximately 3 to 9 log colony-forming units (CFU)/g. Enterobacteriaceae populations were in the range of <1 to approximately 7 log CFU/g, while coliform levels varied from <1 to approximately 6 log CFU/g. Thirty samples (29%) were positive for E. coli, with levels reaching approximately 6 log CFU/g. There were no confirmed positives for E. coli O157:H7, Salmonella, or Listeria monocytogenes. The majority of E. coli isolates (n=73), confirmed by glutamate decarboxylase (gad) PCR, were from group B1 (48%) and group A (32%). Resistance to 16 antibiotics was examined for 73 E. coli isolates, with 11 isolates having resistance to at least one antibiotic, 5 isolates to ≥ 2 antibiotics, and 2 isolates to ≥ 10 antibiotics. In the presence of high levels of background aerobic mesophiles, Salmonella and E. coli O157:H7 grew approximately 1 log CFU/g within 1 day of incubation in plant-based compost and fish emulsion-based compost, respectively. With low levels of background aerobic mesophiles, Salmonella grew approximately 2.6, 3.0, 3.0, and 3.2 log CFU/g in blood, bone, and feather meals and the mixed-source fertilizer, respectively, whereas E. coli O157:H7 grew approximately 4.6, 4.0, 4.0, and 4.8 log CFU/g, respectively. Our results revealed that the microbiological quality of organic fertilizers varies greatly, with some fertilizers containing antibiotic resistant E. coli and a few supporting the growth of foodborne pathogens after reintroduction into the fertilizer.

In situ ruminal crude protein degradability of by-products from cereals, oilseeds and animal origin

The aim of this study was to establish a database on in situ ruminal crude protein (CP) degradability characteristics of by-products from cereal grains, oilseeds and animal origin commonly fed to ruminants in Pakistan and South Asian Countries. The oilseed by-products were soybean meal, sunflower meal, mustard seed meal, cottonseed meal, decorticated and un-decorticated cottonseed cake, maize oil cake and mustard seed cake. The cereal grain by-products were corn gluten meal, corn gluten feed, guar meal, toria meal, rice meal, rice polishings, rice bran and wheat bran. The animal by-products were fish meal, feather meal, blood meal, and meat and bone meal. Four samples per feed were collected from different dairy farms (n=1), local markets (n=1), and agro-food industries (n=2). Ruminal protein degradation characteristics of the feeds were determined using the in situ nylon bag technique where each feed was incubated in the rumen of 3 mature steers for 2, 4, 8, 12, 24 and 48h. There were large differences in instantly soluble (W) fraction, potentially rumen degradable (D) fraction, rate of degradation (kd) and effective degradability of crude protein (EDCP) among the by-product feeds. Among the oilseed by-products, mustard seed cake had the highest (P<0.05) and un-decorticated cottonseed cake had the lowest EDCP values at the three outflow rates (0.02, 0.05 and 0.08/h). Similarly, among cereal grain by-products wheat bran had the highest (P<0.05) and rice bran had the lowest EDCP. The animal by-product based protein feeds had lower kd and EDCP values compared to oilseeds and cereal grain by-product based protein feeds, and can be used to increase the bypass protein. The CP degradation parameters reported in this study can be used to optimize diet formulation for ruminant livestock in terms of protein supply to the animals, and reduce N losses to the environment and increase economic profitability of the dairy farmers.

Codon Optimization Significantly Improves the Expression Level of a Keratinase Gene in Pichia pastoris

The main keratinase (kerA) gene from the Bacillus licheniformis S90 was optimized by two codon optimization strategies and expressed in Pichia pastoris in order to improve the enzyme production compared to the preparations with the native kerA gene. The results showed that the corresponding mutations (synonymous codons) according to the codon bias in Pichia pastoris were successfully introduced into keratinase gene. The highest keratinase activity produced by P. pastoris pPICZαA-kerAwt, pPICZαA-kerAopti1 and pPICZαA-kerAopti2 was 195 U/ml, 324 U/ml and 293 U/ml respectively. In addition, there was no significant difference in biomass concentration, target gene copy numbers and relative mRNA expression levels of every positive strain. The molecular weight of keratinase secreted by recombinant P. pastori was approx. 39 kDa. It was optimally active at pH 7.5 and 50°C. The recombinant keratinase could efficiently degrade both α-keratin (keratin azure) and β-keratin (chicken feather meal). These properties make the P. pastoris pPICZαA-kerAopti1 a suitable candidate for industrial production of keratinases.

Biodegradation of keratin in mineral-based feather medium by thermophilic strains of a new Coprinopsis sp.

The disposal of poultry feather waste is a global environmental problem, so degradation of this waste by microbial or enzymatic, environmentally friendly, means is therefore of significant interest. Considering the high protein content of keratin wastes and their great potential as a source of protein or amino acids, degradation of feather was performed by three strains of a novel thermophilic Coprinopsis sp. The strains grew in a mineral-based medium in which chicken feather was the sole source of carbon and nitrogen, where they decomposed the defatted and powdered feather meal into soluble amino acids fractions. Effective protease productivity was observed following 14, 21, 28 and 35 days of incubation and showed a gradual release of soluble amino acids into the medium, corresponding to a decrease in the dry weight of the substrate. The optimal extracellular cell-free keratinase activity was 32 KU/ml expressed in filtrates of 14-day-old cultures, and the optimal cell-bound keratinase activity was 39.9 KU/ml, expressed in centrifuged 21-day-old mats. All strains expressed optimal keratinase activities at 20.40 °C and pH 9.

Feather keratin hydrolysates obtained from microbial keratinases: effect on hair fiber

BackgroundHair is composed mainly of keratin protein and a small amount of lipid. Protein hydrolysates, in particular those with low molecular weight distribution have been known to protect hair against chemical and environmental damage. Many types of protein hydrolysates from plants and animals have been used in hair and personal care such as keratin hydrolysates obtained from nails, horns and wool. Most of these hydrolysates are obtained by chemical hydrolysis and hydrothermal methods, but recently hydrolyzed hair keratin, feather keratin peptides, and feather meal peptides have been obtained by enzymatic hydrolysis using Bacillus spp in submerged fermentation.ResultsKeratin peptides were obtained by enzymatic hydrolysis of keratinases using Bacillus subtilis AMR. The microorganism was grown on a feather medium, pH 8.0 (1% feathers) and supplemented with 0.01% of yeast extract, for 5 days, at 28°C with agitation. The supernatant containing the hydrolysates was colleted by centrifugation and ultra filtered in an AMICON system using nano–membranes (Millipore – YC05). The Proteins and peptides were analyzed using HPTLC and MALDI-TOF-MS. Commercial preparations of keratin hydrolysates were used as a comparative standard. After five days the feather had been degraded (90-95%) by the peptidases and keratinases of the microorganism. MALDI-TOF mass spectrometry showed multiple peaks that correspond to peptides in the range of 800 to 1079 Daltons and the commercial hydrolysate was in the range of 900 to 1400 Da. HPTLC showed lower molecular mass peptides and amino acids in the enzymatic hydrolysate when compared with the commercial hydrolysate . A mild shampoo and a rinse off conditioner were formulated with the enzymatic hydrolysate and applied to hair fibers to evaluate the hydration, with and without heat, using a Corneometer® CM 825. The hydration was more efficient with heat, suggesting a more complete incorporation of hydrolysates into the fibers. Scanning Electron Microscopy showed deposits of organic matter in the junction of the cuticles that probably collaborates to the sealing of the cuticles, increasing the brightness and softness.ConclusionsThese results show that the enzymatic method to produce keratin peptides for hair care products is an attractive and eco- friendly method with a great potential in the cosmetic industry.

Production and characterization of thermostable metallo-keratinase from newly isolated Bacillus subtilis NRC 3

Novel keratinolytic enzyme (32kDa) secreted by a newly isolated Bacillus strain (Bacillus subtilis NRC3) cultivated in medium containing chicken feather meal was purified and partially characterized in a set of biochemical assays. The purification was carried out by applying a protocol of two successive chromatographic steps; cation exchange chromatography on CM-cellulose and gel filtration on sephadex G-75 columns. The purified enzyme showed a specific activity of 5233units/mg protein against 169units/mg protein for crude extract with 31 fold purification. The enzymatic activity of the purified keratinolytic enzyme stimulated by Na+, K+, Mg2+, Ba2+, Ca2+, and inhibited by entire tested cations and metalloproteinase inhibitors, indicating that it belongs to metallo-keratinase enzymes. The optimum pH and temperature for the purified enzyme were (7.5, 8.0) and (50, 40°C) when using keratin azure and azocasein as substrates, respectively. The purified enzyme was highly stable at broad pH and temperature ranged (5–10) and (20–60°C), respectively. These results suggest that this keratinase may be a useful alternative and ecofriendly route for handling the abundant amount of waste feathers.

Comparison of four feed proteases for improvement of nutritive value of poultry feather meal

Feed industries are seeking new ways to cope with increased raw material costs, and one approach is to apply enzymatic treatment in the production of feed ingredients from animal by-products. Keratinases, a group of proteases, are capable of hydrolyzing keratin-rich material and have been applied in the production of cost-effective feather by-products for use as feed and fertilizers. The current study examined 4 commercial feed proteases from Bacillus subtilis, Bacillus licheniformis PWD-1, Aspergillus niger, and Serratia proteamaculans HY-3 used to hydrolyze chicken feather under different conditions. The degree of keratinolysis was monitored by measuring the release of NH(2) groups using o-phthalaldehyde (OPA) and by scanning electron microscopy. All 4 feed proteases were able to degrade feather at pH 5.5 and 7.0. The degree of hydrolysis was stimulated by the addition of reducing reagents such as dithiothreitol (DTT) and Na(2)SO(3). In general, the protease from B. subtilis was more efficient in degrading feather keratin compared to the other 3 feed proteases at both pH 5.5 and 7.0. For commercial production, the application of protease from B. subtilis is even more advantageous considering the lower cost-in-use.

Comment on “Feather Meal: A previously Unrecognized Route for Reentry into the Food Supply of Multiple Pharmaceuticals and Personal Care Products (PPCPs)”

ADVERTISEMENT RETURN TO ISSUEPREVCorrespondence/Rebut...Correspondence/RebuttalNEXTComment on “Feather Meal: A previously Unrecognized Route for Reentry into the Food Supply of Multiple Pharmaceuticals and Personal Care Products (PPCPs)”Mark BlandView Author Information American Association of Avian Pathologists, 12627 San Jose Boulevard, Suite 202, Jacksonville, Florida, 32223 *E-mail: [email protected]Cite this: Environ. Sci. Technol. 2012, 46, 24, 13555–13556Publication Date (Web):October 29, 2012Publication History Published online29 November 2012Published inissue 18 December 2012https://doi.org/10.1021/es303510zCopyright © 2012 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views463Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (126 KB) Get e-AlertsSUBJECTS:Animal derived food,Antimicrobial agents,Contamination,Food,Pharmaceuticals Get e-Alerts

Response to Comment on “Feather Meal: A Previously Unrecognized Route for Reentry into the Food Supply of Multiple Pharmaceuticals and Personal Care Products (PPCPs)”

ADVERTISEMENT RETURN TO ISSUEPREVCorrespondence/Rebut...Correspondence/RebuttalNEXTResponse to Comment on “Feather Meal: A Previously Unrecognized Route for Reentry into the Food Supply of Multiple Pharmaceuticals and Personal Care Products (PPCPs)”D. C. Love*†‡, R. U. Halden‡§⊥∥, M. F. Davis†‡, and K. E. Nachman†‡#View Author Information† Johns Hopkins Center for a Livable Future, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, United States‡ Department of Environmental Health Sciences, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, United States§ School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, Arizona, United States⊥ Center for Environmental Security, Biodesign Institute, Arizona State University, Tempe, Arizona, United States∥ Center for Health Information & Research, Arizona State University, Tempe, Arizona, United States# Department of Health Policy and Management, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, United States*Phone: 443.287.4761; fax: 410-502-7579; e-mail: [email protected]Cite this: Environ. Sci. Technol. 2012, 46, 24, 13557–13558Publication Date (Web):October 29, 2012Publication History Published online29 November 2012Published inissue 18 December 2012https://doi.org/10.1021/es304181cCopyright © 2012 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views395Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (140 KB) Get e-AlertsSUBJECTS:Animal derived food,Animal feed,Food,Manufacturing,Pharmaceuticals Get e-Alerts

Response to Comment on “Feather Meal: A Previously Unrecognized Route for Reentry into the Food Supply of Multiple Pharmaceuticals and Personal Care Products (PPCPs)”

ADVERTISEMENT RETURN TO ISSUEPREVCorrespondence/Rebut...Correspondence/RebuttalNEXTResponse to Comment on “Feather Meal: A Previously Unrecognized Route for Reentry into the Food Supply of Multiple Pharmaceuticals and Personal Care Products (PPCPs)”D. C. Love†‡*, R. U. Halden‡§∥⊥, M. F. Davis†‡, and K. E. Nachman†‡#View Author Information† Johns Hopkins Center for a Livable Future, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, United States‡ Department of Environmental Health Sciences, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, United States§ School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, Arizona, United States∥ Center for Environmental Security, Biodesign Institute, Arizona State University, Tempe, Arizona, United States⊥ Center for Health Information & Research, Arizona State University, Tempe, AZ, U.S.# Department of Health Policy and Management, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, United States*Phone: 443.287.4761; fax: 410-502-7579; e-mail: [email protected]Cite this: Environ. Sci. Technol. 2012, 46, 23, 13026–13027Publication Date (Web):October 22, 2012Publication History Published online14 November 2012Published inissue 4 December 2012https://doi.org/10.1021/es304180xCopyright © 2012 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views357Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (148 KB) Get e-AlertsSUBJECTS:Animal derived food,Animal feed,Antimicrobial agents,Drug resistance,Pharmaceuticals Get e-Alerts

Comment on “Feather Meal: A Previously Unrecognized Route for Reentry into the Food Supply of Multiple Pharmaceuticals and Personal Care Products (PPCPs)”

Comment on “Feather Meal: A Previously Unrecognized Route for Reentry into the Food Supply of Multiple Pharmaceuticals and Personal Care Products (PPCPs)”

Effects of fish meal quality and fish meal substitution by animal protein blend on growth performance, flesh quality and liver histology of Japanese seabass (Lateolabrax japonicus)

An 8-week growth trial was conducted to evaluate the effects of the quality of fish meal and of replacing prime steam dried fish meal (PFM) with an animal protein blend (APB with 40% poultry by-product meal, 35% meat and bone meal, 20% spray-dried blood meal and 5% hydrolyzed feather meal) on the growth performance, flesh quality and liver histology of Japanese seabass, Lateolabrax japonicus (initial body weight, 76.3±0.2g). Six isoproteic (44% crude protein) and isoenergetic (19MJkg−1 gross energy) diets were formulated. A control diet containing 40% PFM was designed, and 20%, 40%, 60% or 80% of the PFM was replaced by APB, in which lysine, methionine and threonine were balanced as in the control diet with crystallized amino acids; the diets were named PFM, APB20, APB40, APB60 and APB80, respectively. An additional diet with 50% standard steam dried fish meal (SFM) that completely replaced the PFM was formulated with the same profile as the control diet to compare the effect of fishmeal quality. Compared to that of fish fed the PFM diet, feed intake was significantly reduced in the SFM group and accordingly induced a lower specific growth rate (SGR, P<0.05), but this did not significantly affect the feed efficiency rate. Fish fed the diets APB20 and APB40 had comparable growth with those fed the diet PFM (control diet). Fish fed the diet with 24% or higher APB had significantly lower SGR than those fed the diet PFM (P<0.05). The reduced growth was linearly correlated to the graded lower dietary n−3 highly unsaturated fatty acids (HUFA) levels when PFM was replaced by APB. Broken-line analysis on the basis of SGR showed that the optimal level of fish meal replacement with APB was only 18.9%. Fish fed the diet with 24% or higher APB had significantly lower whole-body lipids but higher liver lipids than the PFM group (P<0.05). Polyunsaturated fatty acids (PUFA), n−3 fatty acids, n−3 HUFA and the n−3/n−6 ratio in muscle were significantly reduced at higher substitution levels of PFM by APB (P<0.05). The 18:1n-9, EPA, DHA, PUFA, n−3, n−3 HUFA and n−3/n−6 in fish muscle were significantly correlated with the corresponding dietary contents. There were no significant differences in texture parameters for the raw fillets groups, while some differences were found in the cooked fillets groups. Except for the values of “favorite”, the sensory evaluation of the muscle did not reveal significant differences among the PFM, SFM, APB60 and APB80 groups. Fish fed the PFM and SFM diets exhibited normal liver histological structure. However, high levels of substitution of PFM by APB might induce hepatic steatosis for this species. However, the adverse effects cannot be ignored when the total PFM is replaced by SFM.

Production, one-step purification, and characterization of a keratinolytic protease from Serratia marcescens P3

Applications of keratinases demand efficient production and downstream processing. This work reports the production, purification and partial characterization of a keratinolytic protease from Serratia marcescens P3. The influence of temperature, initial pH and feather meal concentration on enzyme production was investigated using response surface methodology. Maximal protease production (12.5UmL−1) was observed at 18–30°C, 10–24gL−1 feather meal, and pH values of 6.5–8.5. The enzyme was recovered from culture supernatants using aqueous two-phase systems (ATPSs), and higher yields (68%) were obtained in polyethylene glycol (PEG) 4000-sodium citrate and PEG 4000-ammonium sulfate systems. These ATPS were effective for enzyme purification, resulting in an electrophoretically homogeneous protein of 53kDa. Sequencing of tryptic peptides identified this enzyme as a metalloprotease belonging to the serralysin family of metzincins. The purified enzyme showed optimal activity at 40–45°C and pH 6.5, being also active toward azokeratin.

Ethanol Production from Waste Potato Mash by Using Saccharomyces Cerevisiae

Bio-ethanol is one of the energy sources that can be produced by renewable sources. Waste potato mash was chosen as a renewable carbon source for ethanol fermentation because it is relatively inexpensive compared with other feedstock considered as food sources. However, a pretreatment process is needed: specifically, liquefaction and saccharification processes are needed to convert starch of potato into fermentable sugars before ethanol fermentation. In this study, hydrolysis of waste potato mash and growth parameters of the ethanol fermentation were optimized to obtain maximum ethanol production. In order to obtain maximum glucose conversions, the relationship among parameters of the liquefaction and saccharification process was investigated by a response surface method. The optimum combination of temperature, dose of enzyme (α-amylase) and amount of waste potato mash was 95 °C, 1 mL of enzyme (18.8 mg protein/mL) and 4.04 g dry-weight/100 mL DI water, with a 68.86% loss in dry weight for liquefaction. For saccharification, temperature, dose of enzyme and saccharification time were optimized and optimum condition was determined as 60 °C-72 h-0.8 mL (300 Unit/mL) of amyloglucosidase combination, yielded 34.9 g/L glucose. After optimization of hydrolysis of the waste potato mash, ethanol fermentation was studied. Effects of pH and inoculum size were evaluated to obtain maximum ethanol. Results showed that pH of 5.5 and 3% inolculum size were optimum pH and inoculum size, respectively for maximum ethanol concentration and production rate. The maximum bio-ethanol production rate was obtained at the optimum conditions of 30.99 g/L ethanol. Since yeast extract is not the most economical nitrogen source, four animal-based substitutes (poultry meal, hull and fines mix, feather meal, and meat and bone meal) were evaluated to determine an economical alternative nitrogen source to yeast extract. Poultry meal and feather meal were able to produce 35 g/L and 32.9 g/L ethanol, respectively, which is higher than yeast extract (30.8 g/L). In conclusion, waste potato mash was found as a promising carbon source for ethanol fermentation with alternate nitrogen sources.

Digestibility of feed ingredients for the striped surubimPseudoplatystoma reticulatum

Knowledge on apparent digestibility coefficients (ADC) is necessary to maximize the feed efficiency, thus lessening dietary nutrient and energy losses. This study tasks the determination of apparent digestibility of selected feedstuff to striped surubim Pseudoplatystoma reticulatum, a carnivorous, South American catfish of economic importance for fisheries and fish culture alike. Juvenile striped surubim (82.4 ± 17.7 g and 23.0 ± 1.6 cm) was distributed in 21 cylindrical, plastic cages (80 L), housed in seven 1000 L feeding tanks under constant water flow and aeration and conditioned to a two daily meals (20h00m and 22h00m) feeding regimen on a practical, reference diet (RD) (460.0 g kg -1 crude protein (CP); 19.23 kJ g -1 gross energy (GE)]. Test diets were obtained by adding of 1 g kg -1 chromium III oxide and 300 g kg -1 of one the following feedstuffs: fish meal (FM), meat and bone meal (MBM), poultry by-product meal, feather meal, blood meal, soybean meal, wheat bran, corn and corn gluten meal to the RD. After the last daily meal, fish were transferred to cylindrical, conical-bottomed aquaria (200 L) under aeration and continuous water exchange, coupled to refrigerated plastic bottles for faeces collection by sedimentation. Best ADC of protein (99.36%) and energy (86.25%) were recorded for poultry by-product meal and MBM, respectively, which are thus deemed ideal surrogate feedstuffs to FM in the formulation and processing of diets for striped surubim.

Effects of preservation conditions of canine feces on in vitro gas production kinetics and fermentation end products1

This study investigated the effect of chilling and freezing (for 24 h) canine feces on in vitro gas production kinetics and fermentation end product profiles from carbohydrate-rich (in vitro run 1) and protein-rich (in vitro run 2) substrates. Feces were collected from 3 adult retriever-type dogs fed a canned diet for at least 2 wk. Each fecal sample was divided into 3 portions: 1 portion was used immediately as an inoculum (fresh) and the other 2 portions were used after either chilling to 5°C for 30 min and storage in crushed ice for 23.5 h (chilling) or freezing to -20°C for 30 min and storage in a prefrozen (-20°C) container for 23.5 h (freezing). The medium solution for run 1 contained N whereas that for run 2 was N free. Substrates included fructooligosaccharide (FOS), sugar beet pulp, and wheat middlings in run 1 and soybean meal, poultry meat meal, and feather meal in run 2. Gas production kinetics were calculated from cumulative gas production data measured for 72 h. After incubation, fermentation liquids were analyzed for short-chain fatty acids, NH3, and aromatic compounds. For both in vitro runs, chilling feces did not affect gas production kinetics and end product profiles of substrates compared with inocula from fresh feces. Freezing feces decreased the maximum rate of gas production in phase 2 for FOS (P<0.001) and across substrates increased gas produced (P≤0.005) and time of maximum gas production in phase 2 (P<0.001). Furthermore, compared with fresh fecal inocula, inocula from frozen feces resulted in increased overall indole concentrations in run 1 (P=0.006) and indole concentrations from soybean meal and poultry meat meal in run 2 (P<0.001). In run 2, phenol concentrations were greater (P=0.015) for frozen feces than for fresh feces (P=0.015). In conclusion, freezing canine feces for 24 h slightly altered fermentative characteristics of fecal inoculum whereas chilling feces in crushed ice for 24 h maintained fermentative characteristics. Chilling feces in crushed ice is a practical method to preserve feces during transport between laboratories within 24 h for in vitro fermentation studies evaluating dietary ingredients.

Production of keratinolytic enzyme by an indigenous feather–degrading strain Bacillus cereus Wu2

A novel feather-degrading microorganism was isolated from a poultry farm in Taiwan, and was identified Bacillus cereus Wu2 according to 16S rRNA sequencing. The isolated strain produces keratinolytic enzyme using chicken feather as the sole carbon and nitrogen source. The experimental results indicated that the extra carbon sources (glucose, fructose, starch, sucrose, or lactose) could act as a catabolite repressor to the enzyme secretion or keratinolytic activity when keratinous substrates were employed as protein sources. However, addition of 2 g/L of NH(4)Cl to the feather medium increased the enzyme production. The optimum temperature and initial pH for enzyme production were 30°C and 7.0, respectively. The maximum yield of the enzyme was 1.75 kU/mL in the optimal chicken feather medium; this value was about 17-fold higher than the yield in the basal hair medium. The B. cereus Wu2 possessed disulfide reductase activity along with keratinolytic activity. The amino acid contents of feathers degradated by B. cereus Wu2 were higher, especially for lysine, methionine and threonine which were nutritionally essential amino acids and usually deficient in the feather meal. Thus, B. cereus Wu2 could be not only used to enhance the nutritional value of feather meal but is also a potential bioinoculant in agricultural environments.

From biogas energy, biotechnology to new agriculture

Agriculture in the 21st Century is facing new challenges and transformation according to five general trends: commercialisation, internationalisation, science and technology, environment and energy production. In this laboratory, a series of research, development and commercialisation of biogas and enzyme technologies reflect these trends. Anaerobic digestion is a microbial process that converts organic waste into biogas, containing 60–70% methane. A simple thermophilic anaerobic digestion (TAnD) system for poultry manure was developed from the lab to the farm. TAnD at 50 to 60°C produces biogas at high rates and, as a result, the process is efficient and the digester is a compact unit. A pilot plug-flow TAnD was first constructed and operated at NCSU research farm. Multiple benefits of the system were demonstrated. Supported by UNDP, a TAnD to process five tons of manure daily (from 50,000 hens) was constructed in China and has been operating for 20 years. Large scale digesters processing hundreds of tons of manure daily are increasingly popular in China and Europe. Biogas from large digesters can be a significant source of energy to generate electricity or to fuel transportation. Beyond energy production, the digester is a rich source of biomaterials. A feather-degrading bacterium was discovered and isolated from TAnD, and its keratinase enzyme and the gene encoding for the enzyme were subsequently isolated. Genetic manipulation for over-expression and up-scale fermentation have now made the industrial production of the enzyme possible. As a heat-stable protease, the keratinase was found to be useful in processing feather meal, in enhancing feed digestibility and was able to degrade prion proteins (implicated as the disease vector in bovine spongiform encephalopathy).

Identification and characterisation of a Bacillus licheniformis strain with profound keratinase activity for degradation of melanised feather

Significant amount of keratins in the form of feather, hair, hoof and horn are generated annually by the livestock industry. Keratinases are increasingly important in the reprocessing and environmental pollution control of keratin wastes. The aim of this study is to isolate a microbial strain of high keratinase activity and to evaluate its feather degrading potential. Thirty-two keratin degrading microbial strains from farmyard wastes and primary effluent were isolated using a selective medium containing feather meal at 30, 37 and 50 °C. One of the isolates, which demonstrated the highest keratinolytic activity (11.00 ± 0.71 U ml−1) was identified as a species of Bacillus licheniformis based on the 16S rDNA analysis, designated as strain N22 and deposited in a culture collection. Optimum keratinase production by this bacterium was achieved in 32 h using a minimum growth medium containing 1.1% (w/v) feather meal at 50 °C and pH 8.5. The molecular weight of the keratinase was ≈28 kDa as determined using sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) analysis and confirmed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The keratinase reported here significantly degraded melanised feather in 48 h in the absence of reducing agents. There are few reports on the evaluation of feather degrading ability of keratinases using highly resistant melanised feather. The efficient degradation of melanised feathers by this keratinase may offer an environmentally friendly solution to the degradation of feather waste and other organic matter of similar molecular composition.

Apparent nutrient digestibility and mineral availability of protein-rich ingredients in extruded diets for Nile tilapia

Apparent digestibility coefficients (ADC) of gross energy and dry matter (DM) and mineral availability were evaluated for eight protein-rich ingredients (corn gluten meal, soybean meal, cottonseed meal at 280.0 and 380.0 g/kg, poultry by-product meal, meat meal, fish meal and feather meal) in compound diets for Nile tilapia. Chromic oxide was used as inert digestibility marker. Higher ADC values of DM and energy were, respectively, 0.862 and 0.881 for corn gluten meal, 0.811 and 0.888 for poultry by-product meal; 0.729 and 0.731 for feather meal; 0.666 and 0.754 for fish meal; 0.578 and 0.642 for soybean meal; 0.476 and 0.652 for meat meal at 450.0 g/kg; 0.352 and 0.449 for cottonseed meal at 380 g/kg; and 0.251 and 0.324 for cottonseed meal at 280.0 g/kg. The highest average mineral availability was for poultry by-product meal (0.582), and the lowest calcium and phosphorus availability were recorded for cottonseed meal at 280.0 g/kg. Therefore, poultry by-product meal appears to be the best ingredient for using in Nile tilapia diets.