Latest Issue
Issue 10 ， 2017
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Transcriptome sequencing and annotation of the halophytic microalga
Dunaliella salina #Abstract：The unicellular green alga Dunaliella salina is well adapted to salt stress and contains compounds (including β-carotene and vitamins) with potential commercial value. A large transcriptome database of D. salina during the adjustment, exponential and stationary growth phases was generated using a high throughput sequencing platform. We characterized the metabolic processes in D. salina with a focus on valuable metabolites, with the aim of manipulating D. salina to achieve greater economic value in large-scale production through a bioengineering strategy. Gene expression profiles under salt stress verified using quantitative polymerase chain reaction (qPCR) implied that salt can regulate the expression of key genes. This study generated a substantial fraction of D. salina transcriptional sequences for the entire growth cycle, providing a basis for the discovery of novel genes. This first full-scale transcriptome study of D. salina establishes a foundation for further comparative genomic studies.Keywords：Dunaliella salina;Transcriptome profile;Metabolic processes and adjustment;Regulatory metabolism;Salt stress- 20
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Published：2022-01-05 -
Nominal effective immunoreaction volume of magnetic beads at single bead level#
Abstract：Immunomagnetic bead (IMB)-based enzyme-linked immunosorbent assay (ELISA) has been the tool frequently used for protein detection in research and clinical laboratories. For most ELISA reactions the recommended dosage of IMBs is usually according to their weight (mg) or mass fraction (w/v) instead of the bead number. Consequently, the processes occurring in the immediate vicinity of the IMBs have always been ignored by researchers and they cannot be revealed in detail during the ELISA reaction. In this paper, we established the relationship between number of IMBs and colorimetric results, and further proposed a new concept of “nominal effective immunoreaction volume (NEIV)” to characterize a single IMB during ELISA reaction. Results showed that the NEIV of a single IMB has a constant value, which is unrelated to the amount of beads and the concentration of antigen. Optimal results of the colorimetric ELISA are achieved when the incubation volume meets each IMB’s NEIV and is no longer enhanced by increasing the incubation volume. Thus, the reliable and relatively precise number of IMBs for ELISA detection during practical application could be determined. Most importantly, a study using IMB’s NEIV would lay the foundation for a kinetics analysis of IMBs and antigens for future study.Keywords：Nominal effective immunoreaction volume (NEIV);Immunomagnetic bead;Enzyme-linked immunosorbent assay (ELISA);Bead diameter;Mixing mode- 53
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Published：2022-01-05 -
Phenolic compounds participating in mulberry juice sediment formation during storage
Abstract：The stability of clarified juice is of great importance in the beverage industry and to consumers. Phenolic compounds are considered to be one of the main factors responsible for sediment formation. The aim of this study is to investigate the changes in the phenolic content in clarified mulberry juice during storage. Hence, separation, identification, quantification, and analysis of the changes in the contents of phenolic compounds, both free and bound forms, in the supernatant and sediments of mulberry juice, were carried out using high performance liquid chromatographic system, equipped with a photo-diode array detector (HPLC-PDA) and HPLC coupled with quadrupole-time of flight mass spectrometric (HPLC-QTOF-MS/MS) techniques. There was an increase in the amount of sediment formed over the period of study. Total phenolic content of supernatant, as well as free phenolic content in the extracts of the precipitate decreased, whereas the bound phenolic content in the sediment increased. Quantitative estimation of individual phenolic compounds indicated high degradation of free anthocyanins in the supernatant and sediment from 938.60 to 2.30 mg/L and 235.60 to 1.74 mg/g, respectively. A decrease in flavonoids in the supernatant was also observed, whereas the contents of bound forms of gallic acid, protocatechuic acid, caffeic acid, and rutin in the sediment increased. Anthocyanins were the most abundant form of phenolics in the sediment, and accounted for 67.2% of total phenolics after 8 weeks of storage. These results revealed that phenolic compounds, particularly anthocyanins, were involved in the formation of sediments in mulberry juice during storage.Keywords：Mulberry juice;Phenolic compounds;Sediment;Anthocyanin;Antioxidant- 106
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Published：2022-01-05 -
Stability of β-carotene microcapsules with Maillard reaction products derived from whey protein isolate and galactose as coating materials
Abstract：The stability of β-carotene microcapsules using Maillard reaction products (MRPs) derived from whey protein isolate (WPI) and galactose as coating materials, was studied under the varying environmental conditions of temperature, pH, air, incandescent light, and ultraviolet (UV) light. Scanning electron microscopy showed that microcapsules prepared by WPI-galactose MRPs displayed a smooth and less concave-convex surface and that the particle size (D50) of the microcapsules made with WPI-galactose MRPs was smaller than those made with WPI-galactose mixture. The storage stability of β-carotene microencapsulated in WPI-galactose MRPs was remarkably better than that of β-carotene microencapsulated in the WPI-galactose mixture and that of β-carotene crystal, in respect of temperature, pH, air, incandescent light, and UV light measurements. When the storage temperature was increased from 5 to 105 °C, the retention rate of β-carotene microcapsules significantly decreased (P<0.05). When pH values were increased from 1 to 12, the β-carotene retention rate of the microcapsules significantly increased and afterward decreased. Compared with the retention rate of β-carotene microencapsulated in a WPI-galactose mixture, the retention rate of β-carotene microencapsulated in WPI-galactose MRPs was at a maximum between pH 8 and 9. Under the actions of air, incandescent light, and UV light, the retention rates of β-carotene microcapsules in WPI-galactose MRPs and WPI-galactose mixture, as well as in β-carotene crystal, decreased significantly as the storage time increased (P<0.05). Therefore, the use of WPI-galactose MRPs as coating materials can aid in improving the storage stability of β-carotene microcapsules.Keywords：Maillard reaction products (MRPs);Whey protein isolate (WPI);β-Carotene;Microcapsule;Stability- 134
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Published：2022-01-05 -
Optimization of low-abundance protein extraction and abundant protein removal from defatted soybean meal
Abstract：The aim of this study was to optimize the conditions for the extraction of low-abundance proteins (LAPs) and the removal of abundant proteins (APs; β-conglycinin and glycinin) from soybean meal. Single factor and orthogonal experiments were designed to determine the effects of four factors (isopropanol concentration, total extraction time, ultrasonic power, and ultrasonic time) on protein concentration in isopropanol extracts. Proteins in the isopropanol supernatant and the cold acetone precipitate of isopropanol were identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF-MS). The results showed that the optimal conditions were 50% isopropanol, ultrasonic pretreatment for 15 min at 350 W, and a total extraction time of 1 h. Under these conditions, the protein concentration in the isopropanol extracts reached 0.8081 g/L. Many LAPs were detected, including β-amylase, soybean agglutinin, soybean trypsin inhibitor, fumarylacetoacetase-like, phospholipase D alpha 1-like, oleosin, and even some unknown soybean proteins. The soybean APs (β-conglycinin and glycinin) were not found. The method may be useful for discovering new soybean proteins and extracting enough LAPs of soybean to allow further studies of their physiological effects on animals without the influence of APs.Keywords：Protein extraction;Abundant protein;Low-abundance protein;Defatted soybean meal;MALDI-TOF-MS- 17
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Published：2022-01-05 -
Effects of neutral phytase on growth performance and phosphorus utilization in crucian carp (
Carassius auratus )Abstract：A feeding trial was conducted for nine weeks to investigate the effects of partially replacing Ca(H2PO4)2 with neutral phytase on the growth performance, phosphorus utilization, nutrient digestibility, serum biochemical parameters, bone and carcass mineral composition, and digestive-enzyme-specific activity in crucian carp (Carassius auratus). The diets prepared with 0.8%, 0%, and 1.8% Ca(H2PO4)2 (1%=1 g/100 g) supplements were regarded as the P1E0, negative control (NC), and positive control (PC) groups, respectively; the other three experimental diets were prepared with the addition of 200, 300, and 500 U/kg of neutral phytase, respectively, based on the P1E0 group. Three hundred and eighty-four fish ((1.50±0.01) g) were randomly distributed in the six treatments with four replicates each. The fish were initially fed with 2%–3% diets of their body weight per day, with feeding twice daily (08:00 and 16:00), under a 12-h light/12-h dark cycle at the temperature of (27.56±0.89) °C. The results showed that supplemental phytase at different levels in the diet improved the final body weight, average daily gain, feed conversion ratio, phosphorus utilization, and protein efficiency ratio of crucian carp (P<0.05). Phytase supplementation increased the mineral content in serum (P), bone (P, Ca), and carcass (P, Ca, Zn, Na, and Mg) (P<0.05); the trypsin and chymotrypsin activity soared when fed with the phytase-supplemented diets (P<0.05). We may conclude that supplemental dietary neutral phytase improved the growth performance, phosphorus utilization as well as nutrient utilization in crucian carp, and it can be considered an important nutritional replacement for Ca(H2PO4)2.Keywords：Neutral phytase;Crucian carp (Carassius auratus);Growth performance;Phosphorus utilization;Apparent digestibility coefficient;Body composition- 14
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Published：2022-01-05 -
Effects of split applications of nitrogen fertilizers on the Cd level and nutritional quality of Chinese cabbage#
Abstract：Cadmium (Cd) contamination in soil is an increasingly serious problem. Management of plant nutrients has been proposed as a potentially promising strategy for minimizing Cd accumulation in crops grown in contaminated soil. This study investigated the effects of split applications of nitrogen (N) fertilizers on the Cd concentration in Chinese cabbage (Brassica chinensis L.) plants grown in Cd-contaminated soil. Compared with single applications, split applications of ammonium or urea resulted in significantly lower Cd concentrations, and higher biomass production and antioxidant-associated nutritional quality in the edible plant parts. However, when nitrate was used as the N fertilizer, there were no significant differences between the split and single applications for the same parameters. We conclude that a split application could be more beneficial than a single application method when ammonium or urea is used as the N fertilizer for vegetable cultivation in Cd-contaminated soil.Keywords：Fertilization method;Cadmium (Cd);Nitrogen (N);Nutritional quality- 14
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Published：2022-01-05 -
Enucleation of non-invasive tumors in the proximal pancreas: indications and outcomes compared with standard resections
Abstract：Objective:The aim of this study was to evaluate the safety and efficiency of enucleation (EU) for proximal pancreatic non-invasive neoplasms.Methods:Patients with solitary non-invasive neoplasms in the proximal pancreas from January 1998 to April 2014 at the Second Affiliated Hospital of Zhejiang University, Hangzhou, China were included. Different operations and outcomes were analyzed.Results:A total of 123 patients were enrolled. Forty patients (32.5%) underwent EU including 18 patients who had tumors close to the main pancreatic duct (MPD). Sixty-one patients (49.6%) had pancreaticoduodenectomy (PD) performed and 22 (17.9%) underwent central pancreatectomy (CP). Pathological outcomes included neuroendocrine tumors, cystic lesions, and solid pseudopapillary tumors. Operation time, intra-operative blood loss, and duration of hospital stay were significantly reduced in the EU group. PD was associated with the greatest complication rate (55.7%), followed by EU (50%) and CP (40.9%), though the pancreatic fistula rate after EU was the highest (50%), especially in patients with tumors larger than 3 cm and tumors close to the MPD. EU had advantages in the preservation of pancreatic parenchyma and endocrine and exocrine function.Conclusions:EU can be carried out safely and effectively for tumors in the proximal pancreas with improved outcomes compared with standard resections, even if the tumor is larger than 3 cm and close to the MPD.Keywords：Enucleation;Pancreatic fistula;Pancreaticoduodenectomy;Central pancreatectomy- 37
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Published：2022-01-05
Article
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Characteristic differences in essential oil composition of six
Zanthoxylum bungeanum Maxim. (Rutaceae) cultivars and their biological significance#Abstract：Great variations have been found in composition and content of the essential oil of Zanthoxylum bungeanum Maxim. (Rutaceae), resulting from various factors such as harvest time, drying and extraction methods (Huang et al., 2006; Shao et al., 2013), solvent and herbal parts used (Zhang, 1996; Cao and Zhang, 2010; Wang et al., 2011). However, in terms of artificial introduction and cultivation, there is little research on the chemical composition of essential oil extracted from Z. bungeanum Maxim. cultivars, which have been introduced from different origins. In this study, the composition and content of essential oil from six cultivars (I–VI) have been investigated. They were introduced and cultivated for 11 years in the same cultivation conditions. Cultivars were as followings: Qin’an (I) cultivar originally introduced from Qin’an City in Gansu Province; Dahongpao A (II) from She County in Hebei Province; Dahongpao B (III) from Fuping County; Dahongpao C (IV) from Tongchuan City; Meifengjiao (V) from Feng County; and, Shizitou (VI) from Hancheng City, in Shaanxi Province, China. This research is expected to provide a theoretical basis for further introduction, cultivation, and commercial development of Z. bungeanum Maxim.Keywords：Zanthoxylum bungeanum Maxim cultivars;Essential oil;Composition;Characteristic differences;Cluster analysis- 132
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Published：2022-01-05
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