Biotin is a water-soluble B-vitamin with key roles in metabolism and are found in most foods at low concentrations. Symptomatic biotin deficiency is rare, and few studies have investigated biotin requirements in relation to health outcomes. Data to support the setting of dietary reference values for biotin are limited.

Biotin (B7) acts as an antioxidant, as it inhibits the effect of many free radicals that are naturally formed within the organism\'s body. This study aimed to determine the effect of adding different concentrations of biotin to the diet of broilers exposed to oxidative stress in improving productive and physiological performance. 180 unsexed Ross-308 one-day age chicks of broiler chickens were used, and they were reared together until 7 days. Then the chicks were randomly distributed into 5 treatments; each treatment included 3 replicates, 12 chicks for each replicate. Oxidative stress was induced by adding 0.5% H2O2 to drinking water. The first treatment, T1 (control), was free from adding B7 or H2O2, and the second treatment (T2): was a positive control treatment free from adding vitamin B7 + water added to it H2O2 at an average of 0.5%. The third treatment (T3): adding 550 micrograms of B7/kg of feed + water added H2O2 at an average of 0.5%. Fourth treatment (T4): 650 micrograms/kg vitamin B7 + water with 0.5% H2O2 added on average. Fifth treatment (T5): 750 micrograms of vitamin B7/kg of feed + 0.5% H2O2 added to the water. The results of adding vitamin B7 to the diet of T4 and T5 birds exposed to oxidative stress showed a significant increase (P<0.05) in the average live body weight, total weight gain and cumulative feed consumption average, and the best cumulative feed conversion ratio for treated birds (T3, T4, T5). In comparison to the other therapies, all additional vitamin B7 treatments demonstrated a significant decrease (P<0.05) in the concentrations of glucose, cholesterol, triglycerides, as well as Malondialdehyde (MDA), and low-density lipoproteins (LDL) and a significant increase (P<0.05) in the concentrations of high-density lipoproteins (HDL) and total protein. The concentration of glutathione peroxidase (GSH-Px) was significantly elevated (P<0.05) in the serum of T5-treated birds compared to all other treatments. We conclude that adding vitamin B7 in different concentrations improved the productivity and some physiological traits of broilers exposed to the induced oxidative stress compared with the negative and positive control treatments.

Heterodera glycines, the soybean cyst nematode (SCN), is a plant-parasitic nematode capable of manipulating host plant biochemistry and development. Many studies have suggested that the nematode has acquired genes from bacteria via horizontal gene transfer events (HGTs) that have the potential to enhance nematode parasitism. A recent allelic imbalance analysis identified two candidate virulence genes, which also appear to have entered the SCN genome through HGTs. One of the candidate genes, H. glycines biotin synthase (HgBioB), contained sequence polymorphisms between avirulent and virulent inbred SCN strains. To test the function of these HgBioB alleles, a complementation experiment using biotin synthase-deficient Escherichia coli was conducted. Here, we report that avirulent nematodes produce an active biotin synthase while virulent ones contain an inactive form of the enzyme. Moreover, sequencing analysis of HgBioB genes from SCN field populations indicates the presence of diverse mixture of HgBioB alleles with the virulent form being the most prevalent. We hypothesize that the mutations in the inactive HgBioB allele within the virulent SCN could result in a change in protein function that in some unknown way bolster its parasitic lifestyle.

An oxygen requirement for de novo biotin synthesis in Saccharomyces cerevisiae precludes the application of biotin-prototrophic strains in anoxic processes that use biotin-free media. To overcome this issue, this study explores introduction of the oxygen-independent Escherichia coli biotin-biosynthesis pathway in S. cerevisiae. Implementation of this pathway required expression of seven E. coli genes involved in fatty-acid synthesis and three E. coli genes essential for the formation of a pimelate thioester, key precursor of biotin synthesis. A yeast strain expressing these genes readily grew in biotin-free medium, irrespective of the presence of oxygen. However, the engineered strain exhibited specific growth rates 25% lower in biotin-free media than in biotin-supplemented media. Following adaptive laboratory evolution in anoxic cultures, evolved cell lines that no longer showed this growth difference in controlled bioreactors, were characterized by genome sequencing and proteome analyses. The evolved isolates exhibited a whole-genome duplication accompanied with an alteration in the relative gene dosages of biosynthetic pathway genes. These alterations resulted in a reduced abundance of the enzymes catalyzing the first three steps of the E. coli biotin pathway. The evolved pathway configuration was reverse engineered in the diploid industrial S. cerevisiae strain Ethanol Red. The resulting strain grew at nearly the same rate in biotin-supplemented and biotin-free media non-controlled batches performed in an anaerobic chamber. This study established an unique genetic engineering strategy to enable biotin-independent anoxic growth of S. cerevisiae and demonstrated its portability in industrial strain backgrounds.

BACKGROUND: Biotin is popular in hair loss treatment supplements, although the frequency of its deficiency in patients with hair loss has not been established. OBJECTIVES: This work sought to assess the serum levels of biotin in patients with telogen effluvium. METHODS: This case-control study included 60 patients with telogen effluvium and 20 control subjects. Subjects who were on biotin therapy three months prior to the study and those reporting other causes of hair loss were excluded. The scalp of each patient was clinically and dermoscopically examined. Serum biotin levels were measured using enzyme-linked immunosorbent assay kits. RESULTS: Serum levels of biotin were optimal in patients and control groups with no significant difference between the groups. Insignificantly lower biotin levels in elderly patients, smokers, athletes, those with a history of recurrent infections, and women who were pregnant and/or lactating were observed. There was also an insignificant positive correlation between the serum level of biotin and patient age and an insignificant negative correlation between disease duration and patient body mass index. Serum biotin has a weak specificity and sensitivity in differentiating between cases and control subjects or between acute and chronic telogen effluvium. CONCLUSION: There was no significant difference in serum biotin levels between cases and controls or between those with acute or chronic telogen effluvium.

A 67-year-old female with a past medical history of multiple endocrine issues presented for follow-up subsequent to abnormal routine blood testing results. These included low thyroid stimulating hormone (TSH), low parathyroid hormone (PTH), and mildly elevated calcium levels. The presence of hypercalcemia and accompanying low PTH raised the concern for malignancy, while the depressed TSH indicated hyperthyroidism. Review of the patient\'s medications revealed daily supplementation with 5 mg of vitamin B7 (biotin). The biotin was discontinued after suspecting the supplement was interfering with the patient\'s lab values. The labs were repeated one month later. The results showed normalized TSH, PTH, and calcium levels. The increasingly wide-spread use of biotin supplementation and the use of biotin as a component in many of the most common clinical assays has led to a trend of lab errors due to biotin interference. While some physicians are aware of the possibility of skewed results, steps need to be taken to prevent misdiagnosis. This includes ensuring that information about this issue is more widely disseminated, accurately accounting for a patient\'s supplement use, reconciling proper clinical correlation with lab results, and promptly reporting when biotin is determined to be the cause of otherwise unexplained lab errors.

The objective of this study was to evaluate the effect of biotin supplementation on milk yield and the reproductive efficiency in Girolando cows. The study was conducted on a dairy farm located in central Brazil, between April 2012 and December 2016. Thirty-six Girolando cows in their first lactation were used. The cows were distributed in two treatment groups, each with equivalent weight distributions. Control treatment (CT) cows (n = 18) received a diet without any supplemental biotin, whereas biotin treatment (BT) cows (n = 18) received a diet supplemented with 20 mg/day of biotin during lactation. Biotin supplementation caused a significant increase (p = 0.001) in milk yield in the second lactation, and a trend (p = 0.09) toward higher average production during the three lactations was evaluated. There was no statistically significant difference between the treatments in terms of reproductive efficiency. In conclusion, biotin supplementation (20 mg/day) during lactation for Girolando cows reared in a tropical climate is able to increase milk yield, but does not improve reproductive efficiency.

For the first time, interaction of vitamin B7 (VB7) with bovine serum albumin (BSA) was investigated with the aim of developing a method for the analysis of BSA. The interaction of VB7 with BSA was investigated by cyclic voltammetry (CV), linear sweep voltammetry (LSV), and differential pulse voltammetry (DPV) at a multi-walled carbon nanotubes-modified glassy carbon electrode (MWCNTs/GCE). The recorded electrochemical data was combined with UVvis and fluorescence (F) spectroscopic data into a row- and column-wise augmented matrix and resolved by multivariate curve resolution-alternating least squares (MCR-ALS) as an efficient chemometric tool, and this assisted in the further elucidation of the above interaction. Also, with aid of MCR-BANDS method, the absence of rotational ambiguity was verified in the obtained results and we confirmed that the obtained results were unambiguous and reliable. The binding of VB7 to BSA was also modeled by molecular docking methods. Excellent agreement was found between the experimental and computational results. The differences of DPV responses of VB7 in the absence and presence of BSA (ΔI) were found to be linearly related to BSA concentration between 0.5×10(-9) mol L(-1) and 35.0×10(-9) mol L(-1), and a limit of detection (LOD, 3Sb/b) of 0.22×10(-9) mol L(-1) was calculated. Finally, the DPV method was further applied to the determination of serum albumin (SA) in serum samples obtained from Holstein cows and the results were in good agreement with those obtained by a medical diagnostic laboratory whose method was based on traditional cellulose acetate electrophoresis. The MWCNTs/GCE showed enhanced electron transfer kinetics, large electroactive surface area, and was highly sensitive, selective, and stable towards SA determination. The satisfactory analytical performance of the proposed method would make it potentially advantageous for a broad range of biosensing and clinical applications.

Heterodera glycines is a nematode that is highly adapted to manipulate and parasitize plant hosts. The molecular players involved in these interactions have only recently begun to be identified. Here, the sequencing of the second stage juvenile transcriptome, followed by a bioinformatic screen for novel genes, identified seven new genes involved in biosynthesis and salvage of vitamins B₁, B₅, and B₇. With no confirmed reports in the literature, each of these biosynthesis pathways is believed to have been lost in multicellular animals. However, eukaryotic-like introns in the genomic sequences of the genes confirmed eukaryotic origin and nematode-specific splice leaders found on five of the cDNAs confirmed their nematode origin. Two of the genes were found to be flanked by known nematode sequences and quantitative polymerase chain reactions on individual nematodes showed similar and consistent amplification between the vitamin B biosynthesis genes and other known H. glycines genes. This further confirmed their presence in the nematode genome. Similarity to bacterial sequences at the amino acid level suggested a prokaryotic ancestry and phylogenetic analysis of the genes supported a likely horizontal gene transfer event, suggesting H. glycines re-appropriated the genes from the prokaryotic kingdom. This finding complements the previous discovery of a vitamin B₆ biosynthesis pathway within the nematode. However, unlike the complete vitamin B₆ pathway, many of these vitamin B pathways appear to be missing the initial enzymes required for full de novo biosynthesis, suggesting that initial substrates in the pathways are obtained exogenously. These partial vitamin B biosynthesis enzymes have recently been identified in other single-celled eukaryotic parasites and on rhizobia symbiosis plasmids, indicating that they may play an important role in host-parasite interactions and survival within the plant environment.