Addition Of Yolk Research Articles

Effect of Addition of Different Egg Yolks in Basic Tris-Soya Diluent on Quality, Membrane Integrity of Senduro Goat Sperm, and Free Radicals during Storage at Temperature of 4-5° C

Semen diluents need macromolecules to protect sperm from the impact of temperature during storage and the presence of free radicals. The purpose of this study was to examine the effect of adding yolk from different types of eggs to the quality and integrity of the sperm membrane. Fresh semen was diluted with basic tris-soya diluent wich was added with different types of chicken egg yolk, such as local chicken eggs and leghorn chicken eggs. As a control group, fresh semen was diluted with basic tris-soya diluent without the addition of egg yolk. The addition of egg yolk was 20% of the diluent volume. Quality observations include motility and viability of sperm. Sperm motility was observed using a microscope with 200 X magnification. The sperm viability was observed using the eosin and negrosin staining method, then it observed under a microscope with 200 X magnification. The integrity of sperm membrane was observed using the HOST method, and then observed under a microscope with 200 X magnification. Free radicals then observed with MDA test. The results showed that the motility, viability and membrane integrity of sperm only lasted until the 12 hour of storage, with the greatest motility, viability and membrane integrity obtained in diluents with the addition of leghorn chicken egg yolk. The smallest MDA test was 2.72, which obtained from diluents with the addition of leghorn chicken egg yolk. Based on the results of the study it can be concluded that the leghorn chicken egg yolk has the best ability to maintain the quality of Senduro Goat sperm during 4-5°C storage temperature.

The role of low-density lipoprotein diluents to spermatozoa motility on limousine liquid semen during storage at 5°C

The length of the spermatozoa storage process can experience a decrease in quality, so it is not feasible to be disseminated. This study aimed to reduce the declining rate of quality of bovine spermatozoa during storage at 5°C after the addition of egg yolk and Low-Density Lipoprotein (LDL) on diluent medium. The study design used a Completely Randomized Design with a factorial pattern (4 x 5) with replications 3 times, where factor A is an LDL thinner (Al: 20% whole egg yolk (control); A2: 7%; A3: A %; A4: 9%) factor B is the length of storage (B1: first day; B2: second day; B3: third day; B4: fourth day; B4: fifth day). The results showed that the spermatozoa motility of Limousine bovine with low-density lipoprotein diluents had high motility compared to spermatozoa diluted with egg yolk diluents during storage at 5°C, the treatment of low-density lipoprotein can reduce the rate of spermatozoa decreased during storage compared to 20% egg yolk. The best LDL concentration is 8% during storage. The conclusion of this study shows that the administration of LDL could minimize the rate of deterioration in the quality of Limousine bovine spermatozoa during storage compared to egg yolk.

Development of non-dairy creamer analogs/mimics for an alternative of infant formula using egg white, yolk, and soy proteins.

ObjectiveA study was conducted to develop non-dairy creamer analogs/mimics using egg white, egg yolk, soy protein and their combinations, and their nutrient content, shelf-life and flavor acceptability were compared.MethodsSpray dried egg white, egg yolk, and soy protein isolate were purchased from manufacturers and used for the formulae.ResultsThe protein contents of the non-dairy creamer analogs/mimics were about 8.5% as calculated. The amounts of oleic and linoleic acid content increased as the amount of yolk increased in the formula, but the increases of polyunsaturated fatty acids were <0.5% of total fat. Addition of egg yolk to the formula increased choline and lutein content in the products, but the amounts were <0.4 mg/g for choline and 4 μg/g for lutein. The lutein in the products continued to decrease over the storage time, and only about 15% to 20% of the 0-month amounts were left after 3 months of storage. Although the thiobarbituric acid reactive substances values of the spray-dried non-dairy creamer analogs/mimics increased as storage time increased, the values were still low. Yellowness, darkness, and egg flavor/odor of the non-dairy creamer analogs/mimics increased as the amount of egg yolk in the formula increased. The overall acceptability of the non-dairy creamer analogs/mimics was closely related to the intensity of egg flavor/odor, but storage improved their overall acceptance because most of the off-odor volatiles disappeared during the storage. Water temperature was the most important parameter in dissolving spray-dried non-dairy creamer analogs/mimics, and 55°C to 75°C was the optimal water temperature conditions to dissolve them.ConclusionHigher amounts of yolk and soy protein combinations in place of egg white reduced the cost of the products significantly and those products contained better and balanced nutrients than the commercial coffee creamers. However, off-flavor and solubility were two important issues in the products.

Effect of egg yolk on the textural, rheology and structural properties of egg gels

Egg gel is the combined gelation of egg white (EW) and egg yolk (EY); its properties depend on the fixed ratio of EW and EY in shell egg. This study investigated the gelation properties of egg mixtures in artificial blends to explore innovative egg solutions catering to the market demands and provide guidance for the production of creative egg products. Results showed that solubility of samples decreased with the increase of EY proportion while solid content increased. More surface hydrophobicity and total SH group increases were observed with higher EY proportion. Rheological tests suggested that adding EY decreased samples' initial G' values. Egg gel containing 20% EY presented the largest hardness value, which seems to be related to the fine gel network microstructure. Besides, the springiness and water-holding capacity of gels gradually increased with EY addition, which may be the result of dense microstructure and high solid content of EY.

Impact of temperature, nutrients, pH and cold storage on the germination, growth and resistance of Bacillus cereus spores in egg white

B. cereus spores are a concern to the food industry, especially to the producers of heat sensitive food products like egg white or precooked and stored food such as fried rice. This study investigated the impact of nutrients, temperature (4, 8, 15 and 25 °C), pH (4, 5, 7 and 9), and cold storage on the germination, growth and resistance of B. cereus spores. In egg white held at 4 °C for 12 days spore germination was not apparent, however the addition of egg yolk (5%) resulted in a 2 Log colony forming units (CFU)/mL increase in vegetative cells (p < .05). Adding l-alanine (0.9 mg/mL) to egg white did not induce germination unless the spores were simultaneously heat activated at 70 °C for 30 min. On incubation at 15 or 25 °C in egg white, spore germination increased by 3.0 Log and 3.7 Log CFU/mL on day 12. The presence of 5% yolk further enhanced germination and subsequent sporulation during storage at 15 and 25 °C. Acidification (pH 4) of 10% egg white solution prevented germination at 4, 8, 15 and 25 °C. Spores held at 4 °C for 6 days in phosphate buffer (50 mM, pH 4) had visible deformations on their surface (scanning electron microscopy) and a significant reduction in D88, and D92 values of 13.9 and 8.2 min respectively. A better understanding of how spores sense and respond to changing environmental conditions will help in the development of processing strategies, involving multiple hurdles to ensure the prevention of germination and subsequent toxin production.

The relationship of physical and chemical conditions of CEP diluent with egg yolk addition to bull spermatozoa quality before and after storage at temperaturof 4-5°C

Storage of semen requires diluent to dilute semen and maintain sperm quality. One of the diluent for bull semen was CEP. The purpose of this study was to assess the association of bull spermatozoa quality with the physical and chemical conditions of CEP diluents with the addition of egg yolk before and after the storage process. The study used Limousin bull with 5 replications. The quality of spermatozoa included motility and viability. Physical and chemical conditions included the pH and osmolarity of the diluent. The motility of spermatozoa was observed under a light microscope with 200 X magnification at 37°C by two people. The viability of spermatozoa was observed under a light microscope with 400 X magnification with nigrosine eosin staining. Data were analyzed with ANOVA and continued Duncan’s test. Dilution pH was measured using pH indicator paper ranging from 6-8. The osmolarity of the diluent was measured by electrical osmolarity. The results showed that the addition of egg yolk in the CEP diluent decreased the pH and increased osmolartitas, but the quality of spermatozoa can be kept up to 8 days of storage. The conclusion in this study was the addition of egg yolk in the CEP diluent provided physical and chemical conditions that can maintain the quality of spermatozoa during storage at a temperature of 4-5 ° C.

Effects of Different Cytoprotectants Combination on Sperm Survival, Fertility and Embryo Development in Amur Sturgeon (&amp;lt;i&amp;gt;Acipenser schrenckii&amp;lt;/i&amp;gt;)

Development of artificial propagation technology is becoming increasingly important in sturgeon aquaculture whether species recovery efforts or commercial production. The cryopreservation technique of high-quality semen collected during the spawning season could extremely improve reproductive efficiency for year-round availability, especially for off-season use. However, the cryopreservation technique of sperm in Amur sturgeon (Acipenser schrenckii) has not been effectively developed. In the present study, we firstly tested the cryopreservations combination effects of three cryoprotectants, including methanol, dimethyl sulfoxide (DMSO), and propylene glycol (PG) and fresh yolk (Y) addition on sperm motility, fertilization and embryo development in Amur sturgeon. The results indicated that sperm motility was still more than 60% in the MT group but that of the control group was sharply decreased to 4.5% after 72 h of in vitro storage (4°C). The post-thawed sperm motility analysis showed that there was no significant difference between the MT+DMSO group and MT group, but the fertility rate in the MT group was significantly higher with a value of 42.30±2.57(%) than any other experimental groups, including the MT+DMSO group (P<0.05). Meanwhile, we also found that there was no significantly positive effect on post-thawed sperm motility with Y addition. Interestingly, although the results showed that the MT+DMSO group and MT group had similar effects on the post-thawed sperm motility, the MT+DMSO group had higher hatching rate compared to any other tested groups, including the MT group. Meanwhile, we also found that PG as cryoprotectant was unsuitable for sperm cryopreservation of Amur sturgeon. In conclusion, our results provides invaluable basis in further studies for the optimization technology of artificial propagation in Amur sturgeon.

Evaluation of microstructure and quality characteristics of microwave-dried instant noodles enriched with chicken meat, egg yolk, and seaweed

The effects of chicken meat, egg yolk, and seaweed supplementation on microwave-dried instant noodles were investigated to develop protein-enriched instant noodles. The influence of chicken meat significantly (P ≤ 0.05) increased the optimum cooking time and water absorption. Additionally, egg yolk improved the noodle quality by decreasing the cooking loss from 6.51 to 4.25% and increasing the maximum tension force and distance from 0.13 to 0.16 N and from 16.83 to 24.69 mm, respectively, which contrasted with the decrease in the maximum tension force and distance caused by seaweed addition. Scanning electron micrographs of the chicken addition presented large porous structures, while the egg yolk addition resulted in uniform porous structures with a finer connective network; confocal scanning laser micrographs also confirmed good protein distribution. Finally, instant noodles supplemented per 100 g of flour with chicken meat (10 g), egg yolk (10 g), and seaweed (2 g) were selected as optimal. The protein content significantly (P ≤ 0.05) increased from 11.42 to 16.73 g per 100 g dry matter, which was higher than in traditional wheat-based instant noodles and this developed product was preferred by panelists. This knowledge can support innovation in the development of instant noodles with a higher protein content.

PENGARUH PRESENTASE KUNING TELUR ITIK DAN ASAM FORMIAT DALAM PROSES PEMINYAKAN TERHAAP KEKUATAN FISIK KULIT AYAM PEDAGING SAMAK KHROM

The purpose of this study was to find out the effect of ducks yolk and formic acid in fat liquoring process of the tanned skin. The materials used in this study were 30 pieces of 7 weeks of broiler chicken shank. The study was carried out using completely randomized design. The variables measured were softness, tensile strength and stretch of the tanned skin. Data were analyzed by analysis of variance and followed by Duncan’s Multiple Range Test. The research results showed that the addition of ducks yolk and formic acid didn’t gave significantly affect on the softness (p>0.05), while gave highly significant affect on tensile strength and stretch (p 0.05) on the softness and stretch, and have significantly (p<0.05) on the tensile strength of leather. The conclusion of this research the addition of 11% duck yolk and 1% formic acid in fat liquoring is the best treatment for broiler chicken shank chrome tanning on the skin softness (2,667), tensile strength (135,707 kg/cm2), and stretch (37,34%), respectively.

165 THE EFFECT OF INDIGENOUS CHICKEN EGG YOLK SOURCES AND TEMPERATURES ON SHORT-TERM PRESERVATION OF SOUTH AFRICAN INDIGENOUS GOAT SEMEN

Egg yolk is a common constituent of semen extender and protects sperm against cold shock. Besides its protective characteristic, chicken egg yolk is mostly included in extenders for semen preservation due to its abundant availability. The aim of the study was to compare egg yolk sources from different indigenous chicken egg yolk sources and storage temperatures on short-term preservation of South African indigenous goat semen. Semen was collected from 8 South African indigenous goats with artificial vagina during the breeding season (autumn). From each of the 8 goats, 6 replicates were done. Semen samples were randomly allocated into 4 treatment groups of Tris-based extenders containing 20% of egg yolk from White Leghorn as a control, Ovambo, Potchefstroom Koekoek, and Venda chicken breeds. The extended semen samples were stored at 5 or 25°C for 48 h. Semen samples were evaluated for sperm motility using computer-aided sperm analysis sperm viability and morphology with fluorescence microscope at 0, 3, 24, and 48 h. Data was analysed with ANOVA using Stata® version 12 (StataCorp, College Station, TX, USA) statistical software to test the differences between the treatments. The total, progressive, and rapid sperm motility rates were higher in freshly collected semen (90.6, 42.7, and 33.0%, respectively) compared with treatment groups. Semen extended with Tris without egg yolk had higher total sperm motility rate at both 5°C (48.1; 51.1%) and 25°C (43.3; 53.3%) temperatures for 48 h. Semen extended with egg yolk from different egg yolk sources had no sperm motility from 24 h when stored at 25°C. Semen extended with Tris without egg yolk (48.1%) had higher sperm motility than Ovambo, Potchefstroom Koekoek, Venda, and White Leghorn (3.7, 0, 0, and 0.4%, respectively) when stored at 5°C for 48 h. However, sperm motility declined when storage increased. In conclusion, addition of egg yolk had no effect on preserving goat semen. However, Tris-based extender without addition of egg yolk preserved semen for longer period than semen extended with egg yolk regardless of egg yolk origin or chicken breed.

QUALIDADE DO SÊMEN DE TAMBAQUI (Colossoma macropomum) CRIOPRESERVADO EM DIFERENTES CONCENTRAÇÕES DE GEMA DE OVO

Resumo O objetivo deste trabalho foi avaliar o efeito da adição de gema de ovo (GO) sobre a cinética dos espermatozoides de tambaquis após a criopreservação. Utilizaram-se vinte machos de tambaquis (n= 4 pools), que foram induzidos hormonalmente com extrato hipofisário de carpa, para espermiação. Quatorze horas após a indução, realizou-se a coleta seminal. O sêmen de cada pool foi diluído em Ringer adicionado de 10% de dimetilsulfóxido (DMSO) acrescido ou não de GO (T1: sem acréscimo de GO; T2: com 5% de GO e T3: com 10% de GO). O sêmen tratado foi envasado em palhetas de 0,5 mL, congelado em vapor de nitrogênio líquido (dry shipper-30 min/-153 °C) e posteriormente transferidas para nitrogênio líquido. As palhetas foram descongeladas em banho-maria a 37 °C/30 segundos. A taxa de motilidade (%) e a velocidade curvilinear espermática (µm/s) foram analisadas em sistema computadorizado (CASA). Os dados foram expressos em média ± desvio padrão e foi aplicado o teste de Tukey (P&lt;0,05). Houve uma redução significativa na porcentagem de espermatozoides móveis e velocidade curvilinear após a adição de GO independente da concentração. Logo, a adição de GO ao Ringer + DMSO teve efeito negativo sobre a motilidade do sêmen congelado de tambaqui.

Chilled and post-thawed semen characteristics of buffalo semen diluted in tris extender enriched with date palm pollen grains (TPG)

The benefits of dates palm and their pollen grains in the human nourishment system have their consideration and importance in medical and nutritional point of view. The present study aimed to investigate a new perspective for the use of date palm pollen grains (DPPG) aqueous extract or infusion in preservation of chilled and frozen buffalo semen. Pooled buffalo semen were diluted by Tris-Citrate-Fructose egg yolk (TCFY) diluent (considered as control) and diverse concentrations of clarified soaked pollen grains in Tris-Citrate-Fructose (TCF) diluent in concentrations of 50, 100, 150, 200 and 250 mg DPPG/5 mL TCF. Five concentrations were kept without egg yolk (TPG) while other five concentrations contained 20% egg yolk (TPGY). Each of the two dilutions was enumerated according to the concentration of DPPG. Extended semen is then chilled (for 7 d) and cryopreserved. Motility, alive sperm and intact sperm membrane (HOST) % were recorded as characteristic sperm parameters. After 7 d of chilling, significant (P < 0.000 1) high percent of motile sperms was recorded for TPG 50, 100, 150, 200 and 250 (66.67, 65.00, 61.67, 61.67 and 63.33, respectively). After freeze thawing, TPGY 150 and 250 showed the significant (P < 0.000 1) high percent of motile sperms (43.75 and 45.00, respectively) while TPGY 100, 200, 250 and TPG 50, 150 revealed the high results concerning HOST (80.61, 83.99, 80.61, 88.33 and 83.33, respectively) whereas the highest alive sperm percentage was recorded with TPGY 150 (96.30) compared to the control. The aqueous cold infusion or extract of the DPPG, added to the TCF extender with or without the addition of egg yolk, proved its good preserving and maintaining capacity of chilled and thawed buffalo bull sperms which was expressed mainly by the sperm motility.

Optimizing sperm cryopreservation in great scallop (Pecten maximus)

A basic cryopreservation protocol for great scallop sperm was recently published, with which thawed sperm survival remained limited to 25% of control values (Suquet et al. 2014). We designed here a set of five experiments to test ways of improving thawed sperm survival and storage by studying the effects of (1) cryoprotectant concentration; (2) sugar incorporation in the extender; (3) egg yolk addition to the extender; (4) sperm dilution rate; and (5) storage capacity of thawed sperm at 4 degrees C. A sixth experiment was then performed to compare rearing performances of larvae produced using thawed sperm from the optimal protocol defined in the present study with those produced using fresh sperm. During the first experiment, a significantly higher percentage of motile spermatozoa was recorded after thawing when the treatment had included 15 or 20% polyethylene glycol (PEG). In the second experiment, no significant improvement in post-thaw sperm motility was recorded when trehalose or glucose was added to the extender. In the third experiment, adding 10 or 20% egg yolk to the extender significantly decreased the percentage of motile sperm. During the fourth experiment, significantly higher percentages of motile sperm were observed for dilution rates ranging from 3 : 1 to 1 : 1 than for higher dilution rates. In the fifth experiment, a significant decrease in the percentage of post-thawed sperm was observed for storage durations of 30 and 60 min, relative to shorter durations. During the last experiment, similar rearing performances were observed between larvae produced using fresh and thawed sperm, up to 9 days post fertilization. In conclusion, the high survival of sperm recorded after thawing (67% of the control level) and the high rearing performances of progenies obtained using thawed sperm validate the use of the present improved cryopreservation protocol for sperm cryobanking in great scallop.

The Quality of Frozen-thawed Canine Semen With Respect to Semen Extender Composition and Sequence of Ejaculate Collection in Dogs

The aim of this study was to evaluate the effect of clarified egg yolk addition to semen extender, and the semen collection sequence on the quality of frozen-thawed semen in dogs. Semen was collected from 6 dogs in a time interval of 24 hours. As parameter of the quality of frozen-thawed (F-T) semen, the motility by computer assisted sperm analysis (CASA) and plasma membrane integrity by hypo-osmotic swelling test (HOS) were evaluated. All kinematic parameters of sperm motility were higher in F-T samples containing the whole in comparison to the clarified egg yolk. The sequence of semen collection affected sperm movement characteristics of native as well as F-T semen, but it was not possible to determine whether the fresh semen from the 1st or 2nd collection is of higher quality. All motility parameters of sperms frozen with extender containing the whole egg yolk were significantly higher in the case of the 2nd collection. The situation was not so clear in the case of clarified egg yolk addition, but the velocity values were higher in F-T samples from the 2nd collection. In contrast to proven differences in motility, the effect of the addition of clarified egg yolk and the sequence of semen collection were not projected at all on the quality of plasma membrane of canine sperms evaluated by HOS test.

Effect of Ducks Yolk and Formic Acid in Fat Liquoring Process on the Physical Quality of Broiler Chicken Shank Chrome Tanning

The purpose of this study was to find out the effect of ducks yolk and formic acid in fat liquoring process of the tanned skin. The materials used in this study were 30 pieces of 7 weeks of broiler chicken shank. The study was carried out using completely randomized design. The variables measured were softness, tensile strength and stretch of the tanned skin. Data were analyzed by analysis of variance and followed by Duncan’s Multiple Range Test. The research results showed that the addition of ducks yolk and formic acid didn’t gave significantly affect on the softness (p&gt;0.05), while gave highly significant affect on tensile strength and stretch (p&lt;0.01). Interaction between two treatment didn’t gave significantly affect (p&gt;0.05) on the softness and stretch, and have significantly (p&lt;0.05) on the tensile strength of leather. The conclusion of this research the addition of 11% duck yolk and 1% formic acid in fat liquoring is the best treatment for broiler chicken shank chrome tanning on the skin softness (2,667), tensile strength (135,707 kg/cm2), and stretch (37,34%), respectively.

Testing an egg yolk supplemented diet on boars to aid in sperm adaptation at 5°C

In many species, extended semen can be stored at low temperatures to slow bacterial growth. However, boar semen performs poorly at temperatures below 15°C and this poses unique challenges, as it is not easy to maintain a constant 15–19°C during shipment. Some extenders have been formulated with egg yolk for storage at 5°C but the addition of egg yolk is not applicable in the majority of commercial operations. The purpose of this study was to evaluate if boar dietary supplementation with powdered egg yolk imparts any protective effects on sperm quality when stored at 15°C and 5°C for up to 11 days in a conventional extender. Ten boars were fed a commercial diet with the addition of 0.11Kg of powdered egg yolk for 10 weeks. Ejaculates collected on weeks 4, 6, 8, and 10 were processed for storage at both 15°C and 5°C and compared with ejaculates from boars fed a standard diet. Throughout an 11-day storage period, sperm quality was assessed including several motility and morphologic parameters and select plasma membrane properties (fluidity, integrity, and triacylglycerol content). Linear regression models were used to describe effects of treatment, storage day, week and temperature on all sperm parameters. Overall, there were minimal beneficial effects of egg yolk treatment on sperm quality parameters. Sperm from egg yolk supplemented boars did have a slower decline in viability and plasma membrane fluidity than that observed in the control sperm when stored at 5°C (p < 0.001). Additionally, there was an increase in total morphologic abnormalities in sperm from egg yolk fed boars compared to controls at week 10 (p < 0.001). In conclusion, the results of this study do not support a significant benefit to sperm quality or resistance to cold storage when feeding a 10-week dietary supplementation of 0.11Kg powdered egg yolk to crossbred boars.

Extension, osmotic tolerance and cryopreservation of saltwater crocodile (Crocodylus porosus) spermatozoa

Abstract Semen collected from 10 saltwater crocodiles (Crocodylus porosus) was used to investigate sperm in vitro manipulation and preservation. Preliminary studies revealed that phosphate buffered saline (PBS) without Ca2 +, Mg2 + and egg yolk (EY) was a suitable extender for studies of sperm physiology. Spermatozoa diluted in PBS showed no change in survival [% motility (M), rate of sperm movement (R) and % plasma membrane integrity (PI)] when diluted over a range of 1:1 to 1:16. Except for a small decline in PI, there was no change in sperm survival when semen diluted without EY was cooled rapidly to and rewarmed from 0 °C. The addition of EY (0, 5, 10 and 20% v/v) had no beneficial effect on sperm survival when incubated in PBS for 1 h at 30 °C or after 24 h storage at 4 °C. Whilst crocodile spermatozoa exposed to a range of anisotonic media and then returned to solutions of 390 mosM kg− 1 retained their M from 220 to 390 mosM kg− 1, PI remained high in hypotonic media (25–280 mosM kg −1); spermatozoa showed an increase (P

The Effects of Fresh Eggs, Egg White, and Egg Yolk, Separately and in Combination with Salt, on Mixogram Properties

ABSTRACTSalt and eggs are common ingredients in some wheat flour‐based food systems and significantly impact dough mixing behavior. We evaluated the effect of either whole eggs, egg white, or egg yolk on dough formation and properties with the Mixograph. Inclusion of whole eggs in wheat flour dough recipes increased dough development time, dough stability, and dough strength upon further mixing less than inclusion of only egg white. In contrast, egg yolk addition decreased all of these parameters. Salt had a more pronounced impact on dough containing egg yolk than on dough containing egg white. The present observations can be explained in terms of shielding charges of the gluten protein's ionized groups, which largely affects dough mixing behavior. The work demonstrates that in some applications it can be useful to use egg fractions rather than whole eggs.

Development of blood–yolk–polymyxin B–trimethoprim agar for the enumeration of Bacillus cereus in various foods

Blood–yolk–polymyxin B–trimethoprim agar (BYPTA) was developed by the addition of egg yolk, laked horse blood, sodium pyruvate, polymyxin B, and trimethoprim, and compared with mannitol–yolk–polymyxin B agar (MYPA) for the isolation and enumeration of Bacillus cereus (B. cereus) in pure culture and various food samples. In pure culture, there was no statistical difference (p>0.05) between the recoverability and sensitivity of MYPA and BYPTA, whereas BYPTA exhibited higher specificity (p<0.05). To evaluate BYPTA agar with food samples, B. cereus was experimentally spiked into six types of foods, triangle kimbab, sandwich, misugaru, Saengsik, red pepper powder, and soybean paste. No statistical difference was observed in recoverability (p>0.05) between MYPA and BYPTA in all tested foods, whereas BYPTA exhibited higher selectivity than MYPA, especially in foods with high background microflora, such as Saengsik, red pepper powder, and soybean paste. The newly developed selective medium BYPTA could be a useful enumeration tool to assess the level of B. cereus in foods, particularly with high background microflora.

Mycelial Growth of &amp;lt;i&amp;gt;Paecilomyces hepiali&amp;lt;/i&amp;gt; in Various Agar Media and Yield of Fruit Bodies in Rice Based Media

Growth of Paecilomyces hepiali in various agar media and yield of fruit bodies in rice based media were studied. The best growth in agar media was obtained at 25℃ (61.86 mm colony diameter in 14 days). The initial agar media pH range from 6 to 8 was found to be the most favourable for mycelial growth. This study found that agars made with powders of cereal grains alone do not support good mycelial growth of P. hepiali. Addition of peptone improved mycelial growth significantly. The most favourable carbon sources were Mannose, Fructose and Glucose. Organic nitrogen sources were found to be the most preferred. The results demonstrated that brown rice is better than polished rice in yield of fruit bodies. Addition of peptone was found to be quite significant in enhancing yield of fruit bodies. Peptone, as a supplement, gave a better yield than addition of egg yolk, albumen and a mixture of the two. The medium with 40 g brown rice, 0.325 g glucose, 0.65 g sucrose, 2 g peptone and 65 ml corn steep liquor was found to be the most favourable and it yielded 19.3 g of fresh fruit bodies.