Fermentation and quality of yellow pigments from golden brown rice solid culture by a selected Monascus mutant

A single peak (λmax 370) yellow pigment-producing mutant derived from Monascus sp. TISTR 3179 was used for the pigment production in solid rice culture. Various factors affecting yellow tones were investigated. Hom-mali rice variety was the best amongst five Thai local varieties used for fungus culture. It was also better than corn, mungbean, soybean, potato, sweet potato, or cassava tubers. The moisture content and temperature were the key environmental factors affecting the color tones of creamy, tangerine, and golden brown rice solid cultures. The golden brown rice culture gave the highest yellow pigment concentration. Under an optimum room temperature of 28–32 °C, an initial moisture content of 42 %, and 7-day-old inoculum size of 2 % (v/w) the maximum yield at 2,224.63 A₃₇₀U/gdw of yellow pigment was produced. A mellow yellow powder at 550 A₃₇₀U/gdw could be obtained using spray-drying techniques. The powder had a moisture content of 5.15 %, a water activity value of 0.398, a hue angle of 73.70 ° (yellowish orange), high lightness (L*) of 74.63, color saturation (C*) of 28.97, a neutral pH of 7.42, 0.12 % acidity and solubility of 0.211 g/10 ml. It was noteworthy that the Chinese fresh noodle with spray-dried yellow powder showed no discoloration during 8-day storage.     

Quantitative analysis and formulation development of a traditional Thai antihypertensive herbal recipe

The health benefits of herbs and herbal products are gaining more attention in southeast Asia. The World Health Organization (WHO) has been supporting countries to promote application of traditional medicines so that this valuable resource is utilized safely and effectively. In Thailand, many traditional herbal recipes have been established since ancient times. Since then, they have been carefully modified, based on the wisdom of traditional Thai medicine practitioners. For this study, a traditional Thai antihypertensive herbal recipe (TTAH) was selected and studied in detail. According to WHO guidelines, both analysis of a sizeable chemical constituent, and formulation data of a product, are a requirement to support a clinical trial for an herbal recipe. Therefore, high-performance liquid chromatography–mass spectrometry (LC–MS) was used to investigate the chemical fingerprints, chemical constituents, and putative active ingredients of the TTAH. Eight chemical fingerprints were established. Metabolic profiling of 10 possible compounds was also identified and all were shown to be active pharmaceutical compounds. An attempt was also made to prepare a suitable formulation of the TTAH, to standardize the amount of active ingredients per dose, and to improve patient compliance. All evaluated parameters guided us to prepare the TTAH as a capsule. This informative data can be included in part of the chemistry–manufacturing–control guidance prior to phase 1/2 clinical trials.     

A rendezvous with the queen of ion channels: Three decades of ion channel research by David T Yue and his Calcium Signals Laboratory

David T. Yue was a renowned biophysicist who dedicated his life to the study of Ca²⁺ signaling in cells. In the wake of his passing, we are left not only with a feeling of great loss, but with a tremendous and impactful body of work contributed by a remarkable man. David's research spanned the spectrum from atomic structure to organ systems, with a quantitative rigor aimed at understanding the fundamental mechanisms underlying biological function. Along the way he developed new tools and approaches, enabling not only his own research but that of his contemporaries and those who will come after him. While we cannot hope to replicate the eloquence and style we are accustomed to in David's writing, we nonetheless undertake a review of David's chosen field of study with a focus on many of his contributions to the calcium channel field.     

Towards a commercially potential process: Enzymatic recovery of phytosterols from plant oil deodoriser distillates mixture

In order to examine the industrial potential to indirectly isolate phytosterols from deodoriser distillates (DODs), enzymatic transesterification of an industrial rapeseed and soybean oil DOD mixture with bioethanol was investigated using commercial lipases and a few newly immobilised preparations of lipases. The lipases from different sources and differing preparation forms were evaluated, in terms of thermostability, enzyme efficiency, and toleration of ethanol. Lipozyme 435 and Lipozyme NS-40044 TLL were found to be most effective biocatalysts in catalysing ethanolysis of glycerides and steryl esters from DODs. The optimum conditions are 10% enzyme load (wt% of DODs), ethanol/DODs of 3.0:1.0 (mol/mol), water content 0.125% (based on the weight of total mixture), and reaction at 30 °C for 5 h. The results demonstrated that >95% sterols can be recovered as free form (>85% sterol esters were liberated as free sterols within 4 h). With this process, the system was simplified as fatty acid ethyl esters and free sterol as major components, where free sterols can be recovered via solvent extraction or molecular distillation. Furthermore, a reuse study of enzyme in consecutive batch reactions demonstrated an excellent operation stability and reusability of Lipozyme 435 and Lipozyme NS-40044 TLL with the developed process. This work indicated that the industrially refined waste DODs can be directly subjected to an enzymatic process for high efficacy recovery of phytosterol without any pre-process, driven by robust lipase preparations.     

Formulation,Physicochemical Characterization,and In Vitro Study of Chitosan/HPMC Blends-Based Herbal Blended Patches

The current work prepared chitosan/hydroxypropyl methylcellulose (HPMC) blends and studied the possibility of chitosan/HPMC blended patches for Zingiber cassumunar Roxb. The blended patches without/with crude Z. cassumunar oil were prepared by homogeneously mixing the 3.5% w/v of chitosan solution and 20% w/v of HPMC solution, and glycerine was used as plasticizer. Then, they were poured into Petri dish and produced the blended patches in hot air oven at 70 ± 2°C. The blended patches were tested and evaluated by the physicochemical properties: moisture uptake, swelling ratio, erosion, porosity, Fourier transform infrared spectroscopy, differential scanning calorimetry, and X-ray diffraction, and photographed the surface and cross-section morphology under SEM technique. Herbal blended patches were studied by the in vitro release and skin permeation of active compound D. The blended patches could absorb the moisture and became hydrated patches that occurred during the swelling of blended patches. They were eroded and increased by the number of porous channels to pass through out for active compound D. In addition, the blended patches indicated the compatibility of the blended ingredients and homogeneous smooth and compact. The blended patches made from chitosan/HPMC blends provide a controlled release and skin permeation behavior of compound D. Thus, the blended patches could be suitably used for herbal medicine application.KEY WORDS: chitosan, formulation, herbal blended patches, HPMC, Zingiber cassumunar Roxb     

Agrobacterium tumefaciens fur Has Important Physiological Roles in Iron and Manganese Homeostasis, the Oxidative Stress Response, and Full Virulence

In Agrobacterium tumefaciens, the balance between acquiring enough iron and avoiding iron-induced toxicity is regulated in part by Fur (ferric uptake regulator). A fur mutant was constructed to address the physiological role of the regulator. Atypically, the mutant did not show alterations in the levels of siderophore biosynthesis and the expression of iron transport genes. However, the fur mutant was more sensitive than the wild type to an iron chelator, 2,2′-dipyridyl, and was also more resistant to an iron-activated antibiotic, streptonigrin, suggesting that Fur has a role in regulating iron concentrations. A. tumefaciens sitA, the periplasmic binding protein of a putative ABC-type iron and manganese transport system (sitABCD), was strongly repressed by Mn²⁺ and, to a lesser extent, by Fe²⁺, and this regulation was Fur dependent. Moreover, the fur mutant was more sensitive to manganese than the wild type. This was consistent with the fact that the fur mutant showed constitutive up-expression of the manganese uptake sit operon. Fur_At showed a regulatory role under iron-limiting conditions. Furthermore, Fur has a role in determining oxidative resistance levels. The fur mutant was hypersensitive to hydrogen peroxide and had reduced catalase activity. The virulence assay showed that the fur mutant had a reduced ability to cause tumors on tobacco leaves compared to wild-type NTL4.     

Agrobacterium tumefaciens fur has important physiological roles in iron and manganese homeostasis, the oxidative stress response, and full virulence

In Agrobacterium tumefaciens, the balance between acquiring enough iron and avoiding iron-induced toxicity is regulated in part by Fur (ferric uptake regulator). A fur mutant was constructed to address the physiological role of the regulator. Atypically, the mutant did not show alterations in the levels of siderophore biosynthesis and the expression of iron transport genes. However, the fur mutant was more sensitive than the wild type to an iron chelator, 2,2'-dipyridyl, and was also more resistant to an iron-activated antibiotic, streptonigrin, suggesting that Fur has a role in regulating iron concentrations. A. tumefaciens sitA, the periplasmic binding protein of a putative ABC-type iron and manganese transport system (sitABCD), was strongly repressed by Mn(2+) and, to a lesser extent, by Fe(2+), and this regulation was Fur dependent. Moreover, the fur mutant was more sensitive to manganese than the wild type. This was consistent with the fact that the fur mutant showed constitutive up-expression of the manganese uptake sit operon. Fur(At) showed a regulatory role under iron-limiting conditions. Furthermore, Fur has a role in determining oxidative resistance levels. The fur mutant was hypersensitive to hydrogen peroxide and had reduced catalase activity. The virulence assay showed that the fur mutant had a reduced ability to cause tumors on tobacco leaves compared to wild-type NTL4.     

Affinity purification of antibodies by using Ni2+-resins on which inclusion body-forming proteins are immobilized

Bacterially expressed recombinant proteins are widely used for producing specific antibodies. Unfortunately, many recombinant proteins are recovered as insoluble materials, so-called inclusion bodies. Inclusion bodies are rather advantageous from a point of view of immunogens because fairly pure proteins can be feasibly extracted from the inclusion bodies. However, we encounter a problem with an insoluble protein when we make an antigen-immobilized column for affinity purification of antibodies because we need a soluble protein in usual immobilization methods. Histidine-tagged proteins can be bound to Ni(2+)-resins in buffer containing 6M guanidine-HCl, in which most insoluble proteins are solubilized. Taking advantage of this feature, we have successfully purified antigen-specific antibodies by directly using Ni(2+)-resins onto which denatured proteins are bound.