Culture conditions influencing phytase production of Mitsuokella jalaludinii, a new bacterial species from the rumen of cattle

AIMS

The effects of pH, temperature, phytate, glucose, phosphate and surfactants on the phytase production of Mitsuokella jalaludinii, a new bacterial species from the rumen of cattle, were evaluated.

METHOD AND RESULTS

By using batch fermentation, it was found that phytase production of M. jalaludinii was induced by sodium phytate. Inclusion of glucose into rice bran-soybean milk (RB-SM) medium inhibited the phytase production. Supplementation of 0.05-0.5% of phosphate to RB-SM medium neither inhibited nor stimulated the phytase production. The optimum pH and temperature for the phytase production of M. jalaludinii were 7.02 and 39 degrees C, respectively. Surfactants such as Tween-80 (0.5% and 1.0%) and Triton X-100 (1.0%) did not affect the phytase production.

CONCLUSIONS, SIGNIFICANCE AND IMPACT OF THE STUDY

The study has provided important data on the culture conditions affecting phytase production of M. jalaludinii, which will facilitate future research on the optimization of fermentation processes for production of high phytase activity by M. jalaludinii.

Efficacy of supplementation of a phytase-producing bacterial culture on the performance and nutrient use of broiler chickens fed corn-soybean meal diets

We evaluated the efficacy of supplementation of active Mitsuokella jalaludinii culture (AMJC) on the growth performance, nutrient use, and mineral concentrations in tibia bone and plasma of broiler chickens fed corn-soybean meal diets. Dietary treatments included low-nonphytate P (NPP) feed (containing 0.24% and 0.232% NPP for chicks from 1 to 21 and 22 to 42 d of age, respectively), low-NPP feed added with different levels of AMJC (equivalent to 250, 500, 750, and 1,000 U phytase/kg of feed), and normal-NPP feed (containing 0.46 and 0.354% NPP for chicks from 1 to 21 and 22 to 42 d of age, respectively). Supplementation of AMJC to low-NPP feed increased (P < 0.05) weight gain and feed intake and decreased (P < 0.05) feed:gain ratio of chickens during the whole experiment (Days 1 to 42). Supplementation of AMJC increased (P < 0.05) the AME value, digestibility of DM and CP, and retention of P, Ca, and Cu. Mn retention in broilers was only increased (P < 0.05) by AMJC supplementation from 18 to 20 d of age, and Zn retention was improved (P < 0.05) only at a high level of AMJC (equivalent to 1,000 U phytase/kg of feed) supplementation. Chicks fed low-NPP feed added with AMJC had similar tibia ash percentages as those fed the normal-NPP diet. Generally, supplementing AMJC to low-NPP feed increased (P < 0.05) Ca, decreased significantly (P < 0.05) Mn and Cu, but did not affect Zn and P concentrations in tibia ash. Supplementing AMJC also increased (P < 0.05) plasma P but had no effect on plasma Ca or Mn. Plasma Zn concentration was increased only when a high level of AMJC (equivalent to 1,000 U phytase/kg of feed) was used. In conclusion, AMJC supplementation to low-NPP feed improved growth performance; AME value; digestibility of CP and DM; use of Ca, P, and Cu; and bone mineralization.

Mitsuokella jalaludinii sp. nov., from the rumens of cattle in Malaysia

Five strains of phytase-producing, gram-negative, non-spore-forming, non-motile, small, stout, rod-shaped, strictly anaerobic, fermentative bacteria were isolated from the rumens of cattle in Malaysia. All five strains had morphological, physiological and biochemical features in common. Although these strains had many physiological and biochemical characteristics that were identical to those of the Mitsuokella multacida type strain (ATCC 27723T), they could be distinguished from this species by means of the following characteristics: a smaller cell size (1.2-2.4 microm long and 0.6-0.8 microm wide); a lower final pH value (3.8-4.0) in peptone/yeast extract/glucose broth; inhibition by 0.001% brilliant green; insensitivity to kanamycin (100 microg ml(-1)) and penicillin (10 microg ml(-1)); a higher optimum growth temperature (approx. 42 degrees C); the ability to grow at 45 and 47 degrees C; the ability to ferment glycerol, sorbitol and amidon; and the inability to ferment mannitol, rhamnose, D-tagatose and melezitose. The G+C content of the type strain (M 9T) of these five strains was 56.9 mol%. Analysis of the 16S rRNA gene sequence of type strain M 9T indicated that the strain falls within the genus Mitsuokella. The sequence similarity between type strain M 9T and Mitsuokella multacida was 98.7%. The DNA-DNA relatedness between type strain M 9T and Mitsuokella multacida type strain DSM 20544T (= ATCC 27723T) was 63.8%, indicating that, in spite of a high level of similarity for the 16S rRNA gene sequence, type strain M 9T is independent of Mitsuokella multacida at the species level. On the basis of these results, a new species, Mitsuokella jalaludinii sp. nov., is proposed for these strains. The type strain is M 9T (= DSM 13811T = ATCC BAA-307T).

Energy expenditure in relation to activity of lesser mouse deer (Tragulus javanicus)

Heat production (HP) of male and female mouse deer during eating, standing and sitting was determined using the open circuit respiration chamber (RC). The time taken for similar activities was also determined in an outdoor enclosure (OD). The animals were fed kangkong (Ipomoea aquatica), sweet potato (Ipomoea batatas) and rabbit pellet ad libitum. Male mouse deer consumed more dry matter (DM), organic matter (OM) and gross energy (GE) than female. The time for each activity of male and female mouse deer kept in RC and OD was similar. The average time spent in RC and OD for both male and female, respectively, for sitting (956 and 896 min/day) was significantly (P<0.01) longer than standing (463 and 520 min/day) and eating (21 and 24 min/day). Heat production for male and female mouse deer, respectively, during eating was the highest (0.44 and 0.43 kJ/kg W(0.75)/min) followed by standing (0.37 and 0.33 kJ/kgW(0.75)/min) and sitting (0.26 and 0.26 kJ/kg W(0.75)/min). The difference in HP per min during standing between male and female was significant (P<0.05). The HP for 08.00-14.00 h and 14.00-20.00 h periods were higher than 20.00-02.00 h and 02.00-08.00 h periods. The overall HP for males during 08.00-14.00 h and 14.00-20.00 h periods were significantly (P<0.05) higher (114.8 and 119.2 kJ/kg W(0.75)) than female (107.5 and 110.4 kJ/kg W(0.75)), respectively.

Digestive and bacterial enzyme activities in broilers fed diets supplemented with Lactobacillus cultures

A study was carried out to investigate the effects of adherent Lactobacillus cultures on 1) amylolytic, lipolytic, and proteolytic enzyme activities in the contents of the small intestine (from the distal end of the duodenum to the ileocecal junction) and 2) bacterial beta-glucuronidase and beta-glucosidase activities in the intestinal contents and feces of broiler chickens. Three dietary treatments were randomly assigned to three groups of chicks, i.e., basal diet only (control group), basal diet + 0.1% dried culture of Lactobacillus acidophilus, and basal diet + 0.1% dried culture of a mixture of 12 Lactobacillus strains. The results showed that supplementation of the adherent Lactobacillus cultures to chickens, either as a single strain of L. acidophilus or as a mixture of 12 Lactobacillus strains, increased significantly (P < 0.05) the levels of amylase in the small intestine. However, the proteolytic and lipolytic activities in the small intestine were not affected by addition of either of the adherent Lactobacillus cultures. Addition of either L. acidophilus or a mixture of 12 Lactobacillus strains was also found to reduce significantly (P < 0.05) the intestinal and fecal beta-glucuronidase and fecal beta-glucosidase but not the intestinal beta-glucosidase at 40 d of feeding.

Skin prick test reactivity to foods in adult Malaysians with rhinitis

The aim of the study was to determine the incidence of food and house dust mite (HDM) allergy in patients with nasal congestion and rhinorrhea attending the Otorhinolaryngology Clinic, National University of Malaysia, Kuala Lumpur. This was a prospective matched, controlled study of patients skin prick tested with commercial food and common aeroallergens. The participants were 148 Malaysian adults with symptoms of nasal congestion and rhinorrhea and 113 adult Malaysian control subjects without rhinitis symptoms. The skin prick test (SPT) was used to evaluate 11 foods common to the Malaysian diet and 3 HDM inhalants. Forty-eight percent of the patients with rhinitis had positive SPT results to foods, compared with 4.4% of control subjects (P < 0.05). The most commonly implicated foods were shrimp (48%) and rice (30%), which are common in the Malaysian diet. Seventy-two percent of rhinitis patients had positive SPT results to HDM, compared with 22.2% of control subjects (P < 0.05). Patients with rhinitis also had significantly more gastrointestinal problems than control subjects (P < 0.05). The incidences of HDM and food allergy are significantly greater in Malaysian adults with rhinitis symptoms than in control subjects without rhinitis. The effect of avoidance or immunotherapy awaits further study.

A comparison of commonly used anti-emetics for the prevention of emetic sequelae after a major gynaecological surgery

STUDY DESIGN

Prospective, randomized, double-blind, placebo-controlled study involving one hundred ASA I-II patients undergoing major gynaecological surgery.

OBJECTIVE

To study anti-emetic efficacy of intravenous (IV) ondansetron (4 mg), droperidol (2.5 mg), metoclopramide (10 mg), and placebo.

PATIENTS AND METHODS

100ASA physical status I-II undergoing major gynaecological surgery were randomized to receive intravenously (IV), one of the four test drugs 10 minutes before the end of anaesthesia. The incidence of postoperative nausea and vomiting following a standard anaesthetic technique was assessed.

RESULTS

A significantly large number of patients who received ondansetron (88%) and droperidol (72%) were free of emetic sequelae when compared to placebo (41%); p < 0.05 (power of this observation is approximately 80% at the given significance level). Metoclopramide was ineffective. Patients given droperidol were significantly more sedated than those receiving ondansetron; p < 0.05. This is not surprising, as the dose of droperidol used in this study was higher than that currently recommended because we found lower doses to be ineffective in controlling nausea and vomiting in this group of patients.

CONCLUSION

It was concluded that, of the drugs studied ondansetron is the best choice for anti-emetic prophylaxis after major gynaecological surgery.

Survey of fungal counts and natural occurrence of aflatoxins in Malaysian starch-based foods

In a survey of starch-based foods sampled from retail outlets in Malaysia, fungal colonies were mostly detected in wheat flour (100%), followed by rice flour (74%), glutinous rice grains (72%), ordinary rice grains (60%), glutinous rice flour (48%) and corn flour (26%). All positive samples of ordinary rice and glutinous rice grains had total fungal counts below 10(3) cfu/g sample, while among the positive rice flour, glutinous rice flour and corn flour samples, the highest total fungal count was more than 10(3) but less than 10(4) cfu/g sample respectively. However, in wheat flour samples total fungal count ranged from 10(2) cfu/g sample to slightly more than 10(4) cfu/g sample. Aflatoxigenic colonies were mostly detected in wheat flour (20%), followed by ordinary rice grains (4%), glutinous rice grains (4%) and glutinous rice flour (2%). No aflatoxigenic colonies were isolated from rice flour and corn flour samples. Screening of aflatoxin B1, aflatoxin B2, aflatoxin G1 and aflatoxin G2 using reversed-phase HPLC were carried out on 84 samples of ordinary rice grains and 83 samples of wheat flour. Two point four percent (2.4%) of ordinary rice grains were positive for aflatoxin G1 and 3.6% were positive for aflatoxin G2. All the positive samples were collected from private homes at concentrations ranging from 3.69-77.50 micrograms/kg. One point two percent (1.2%) of wheat flour samples were positive for aflatoxin B1 at a concentration of 25.62 micrograms/kg, 4.8% were positive for aflatoxin B2 at concentrations ranging from 11.25-252.50 micrograms/kg, 3.6% were positive for aflatoxin G1 at concentrations ranging from 25.00-289.38 micrograms/kg and 13.25% were positive for aflatoxin G2 at concentrations ranging from 16.25-436.25 micrograms/kg. Similarly, positive wheat flour samples were mostly collected from private homes.

Growth performance, intestinal microbial populations, and serum cholesterol of broilers fed diets containing Lactobacillus cultures

A study was conducted to determine the effects of adherent Lactobacillus culture on growth performance, intestinal microbial population, and serum cholesterol level of broilers. Four dietary treatments, consisting of the basal diet (control), basal diet + 0.05, 0.10, or 0.15% Lactobacillus culture (LC), were fed to 2,000 Arbor Acres broiler chicks from 1 to 42 d of age (DOA). The chicks were randomly assigned to 40 cages (50 chicks per cage, 10 cages per diet). The experimental period was 42 d. Body weights and feed to gain ratio were measured at 21 and 42 DOA. The intestinal microbial populations and serum cholesterol levels were determined at 10, 20, 30, and 40 DOA. The results showed that body weights and feed to gain ratios were improved significantly (P < 0.05) when compared to control broilers for broilers fed diets containing 0.05 or 0.10% LC, but not 0.15% LC, at 21 and 42 DOA. Coliform counts in the cecum of birds receiving 0.05% LC at 10, 20, and 30 DOA, and 0.10% at 10 and 20 DOA were significantly lower (P < 0.05) than those of the control birds. The total aerobes, total anaerobes, lactobacilli, and streptococci in the small intestines and ceca of the control birds were not significantly different from those of the treated groups. Serum cholesterol levels were significantly lower (P < 0.05) in broilers fed the three diets containing LC at 30 DOA, and in the birds fed 0.05 or 0.10% LC at 20 DOA.

Acid and bile tolerance of Lactobacillus isolated from chicken intestine

Twelve Lactobacillus strains isolated from chicken intestine were used to investigate acid and bile tolerance in vitro. Ten out of the 12 strains were slightly affected by 0.3% bile salts, showing a delay of growth (d) of 0.6-37.2 min compared with growth in control cultures. Two strains were not affected by the bile salts. Of the 12 strains, seven could be arbitrarily classified as resistant (d < 15 min) and five as tolerant (15 min < d < or = 40 min). Lactobacillus strains from the caecum showed better tolerance to acid than those from the ileum. Generally, the survival of the ileal strains was very low at pH 1.0 and 2.0, and moderate at pH 3.0. In contrast, caecal Lactobacillus strains could survive at pH 1.0 for up to 2 h of incubation; growth was moderate at pH 2.0 and good at pH 3.0 and 4.0.

Note: lack of influence of adherent Lactobacillus isolates on the attachment of Escherichia coli to the intestinal epithelial cells of chicken in vitro

Two Lactobacillus isolates, Lact. acidophilus I 26 and Lact. fermentum I 25, were selected, based on their poor aggregation with Escherichia coli and strong ability to adhere to ileal epithelial cells (IEC), to study in vitro interactions with E. coli O1:K1, O2:K1 and O78:K80 in an IEC radioactive-assay under the conditions of exclusion (lactobacilli and IEC, followed by the addition of E. coli), competition (lactobacilli, IEC and E. coli together) and displacement (E. coli and IEC, followed by the addition of lactobacilli). The results indicated that Lact. acidophilus I 26 and Lact. fermentum I 25 could not significantly reduce the attachment of E. coli O1:K1, O2:K1 and O78:K80 to IEC under the three conditions tested in vitro, except that the attachment of E. coli O1:K1 was slightly reduced by Lact. fermentum I 25 in the test for competition.

Insulin-mimetic agents vanadate and pervanadate stimulate glucose but inhibit amino acid uptake

The protein tyrosine phosphatase (PTP) inhibitors vanadate and pervanadate (pV) exert insulin-like biologic effects. In cultured differentiated rat L6 skeletal muscle cells, vanadate and pV stimulated 2-deoxy-D-[3H]glucose uptake in a dose- and time-dependent manner. There was no increase in maximum stimulation by additional insulin. In contrast, whereas insulin stimulated [14C]methylaminoisobutyric acid (MeAIB) uptake, basal uptake was inhibited by vanadate and pV. Insulin-stimulated MeAIB uptake was also inhibited in a dose-dependent manner and completely abolished by 5 mM vanadate or 0.1 mM pV. The inhibitory effect on basal MeAIB uptake was associated with a decrease in transporter affinity and a small decrease in maximum transport capacity, whereas the insulin-stimulated increase in maximum transport capacity was completely inhibited. Inhibition of MeAIB uptake by vanadate and pV was not blocked by cycloheximide, and oubain did not inhibit uptake. Vanadate also inhibited amino acid deprivation-stimulated MeAIB uptake. Insulin-stimulated MeAIB uptake was also inhibited in rat hepatoma cells. Thus vanadate and pV mimic insulin to stimulate glucose uptake but inhibit system A amino acid uptake. The relative inhibitory concentrations of vanadate and pV suggest that the mechanism may involve PTP inhibition.

Effect of adherent Lactobacillus spp. on in vitro adherence of salmonellae to the intestinal epithelial cells of chicken

Single strains of Lactobacillus acidophilus and Lact. fermentum, isolated from chicken intestine, were used to study in vitro interactions with Salmonella enteritidis, Salm. pullorum or Salm. typhimurium in an ileal epithelial cell (IEC) radioactive assay. Exclusion, competition and displacement phenomena were investigated by respectively incubating (a) lactobacilli and IEC together, prior to addition of salmonellae, (b) lactobacilli, IEC and salmonellae together, and (c) salmonellae and IEC, followed by the lactobacilli. Lactobacilli were selected for study because of their strong ability to adhere to IEC and poor aggregation with salmonellae. The results demonstrated that Lact. acidophilus significantly reduced (P < 0.05) the attachment of Salm. pullorum to IEC in the tests for exclusion and competition, but not in the displacement tests. Lactobacillus fermentum was found to have some ability to reduce the attachment of Salm. typhimurium to IEC under the conditions of exclusion (P < 0.08), competition (P < 0.09), but not displacement. However, both Lact. acidophilus and Lact. fermentum were unable to reduce the adherence of Salm. enteritidis to IEC under any of the conditions.