Whole fruit staining with aniline blue at harvest is associated with superficial pathogenesis of “Fuji” apples after storage

Abstract

Whole “Fuji” apples (Malus domestica Borkh cv. Fuji) were treated with 0.2% aniline blue before storage in 2006, 2007 and 2008 to determine whether cuticular microcracking was associated with post-storage disorders. After storage for 7 months at 0° C and 90% relative humidity followed by 3 days at 20° C, a higher aniline blue staining scale value was associated with a higher peel browning and decay index. These results indicate that superficial disorders or diseases of apples may be related to cuticular microcracking that can be seen by aniline blue staining. Scanning electron microscopy was used to analyze the ultrastructure of stained portions of the cuticular complex. Disorders or diseases of the cuticle of epidermal tissue was associated with cracked lenticels, unhealed microcracks around the edge of the lenticel, and collapsed epicuticular wax; these areas stained more intensely. Our results indicated the potential of using an aniline blue staining prior to storing the fruit to predict the ultimate quality.     

Twoplex 12/13C6 aniline stable isotope and linkage‐specific sialic acid labeling 2D‐LC‐MS workflow for quantitative N‐glycomics

Quantitative glycomics represents an actively expanding research field ranging from the discovery of disease‐associated glycan alterations to the quantitative characterization of N‐glycans on therapeutic proteins. Commonly used analytical platforms for comparative relative quantitation of complex glycan samples include MALDI‐TOF‐MS or chromatographic glycan profiling with subsequent data alignment and statistical evaluation. Limitations of such approaches include run‐to‐run technical variation and the potential introduction of subjectivity during data processing. Here, we introduce an offline 2D LC‐MS^E workflow for the fractionation and relative quantitation of twoplex isotopically labeled N‐linked oligosaccharides using neutral ¹²C₆ and ¹³C₆ aniline (Δmass = 6 Da). Additional linkage‐specific derivatization of sialic acids using 4‐(4,6‐dimethoxy‐1,3,5‐trizain‐2‐yl)‐4‐methylmorpholinium chloride offered simultaneous and advanced in‐depth structural characterization. The potential of the method was demonstrated for the differential analysis of structurally defined N‐glycans released from serum proteins of patients diagnosed with various stages of colorectal cancer. The described twoplex ¹²C₆/¹³C₆ aniline 2D LC‐MS platform is ideally suited for differential glycomic analysis of structurally complex N‐glycan pools due to combination and analysis of samples in a single LC‐MS injection and the associated minimization in technical variation.     

Structural analysis of the curdlan-like exopolysaccharide produced by Cellulomonas flavigena KU

Cellulomonas flavigena KU produces large quantities of an insoluble exopolysaccharide (EPS) under certain growth conditions. The EPS has previously been shown to be a glucose polymer and to have solubility properties similar to curdlan, a β-1,3-D-glucan produced by Alcaligenes faecalis var. myxogenes 10C3K. Furthermore, EPS purified by alkaline extraction stains with aniline blue, a dye specific for curdlan-type polysaccharides. However, EPS-producing colonies of C. flavigena KU do not stain on aniline blue agar as do those of curdlan-producing bacteria. These facts prompted a more thorough structural analysis of the EPS. Here we report that purified EPS is indeed identical to curdlan in primary structure, but that the native form of the EPS may differ from curdlan in physical conformation. Journal of Industrial Microbiology & Biotechnology (2002) 29, 200–203 doi:10.1038/sj.jim.7000277 Received 19 February 2002/ Accepted in revised form 20 May 2002     

Biodegradation of nitrobenzene by a sequential anaerobic-aerobic process

Nitrobenzene was completely degraded by mixed cultures using a sequential anaerobic-aerobic treatment process. Under anaerobic conditions in a fixed-bed column aniline was formed from nitrobenzene through gratuitous reduction by cells of sewage sludge. This reaction was accelerated by the addition of glucose. Complete mineralization of aniline was accomplished by subsequent aerobic treatment using activated sludge as inoculum. The maximum degradation rate of nitrobenzene (4.5 mM) in the two-stage system was 552 mg l^–1d^–1, referring to 154 mg of nitrobenzene per gram of glucose. In a second experimental phase glucose as cosubstrate and H-donor was replaced by synthetic waste containing ethanol, methanol, isopropanol and acetone. Again, nitrobenzene (1.9 mM) was completely degraded (maximum degradation rate of 237 mg l^–d^–1, referring to 251 mg per gram of solvents). The major advantage of the described two-stage process is that the reduction of nitrobenzene by anaerobic pretreatment drastically reduces emission by stripping during aerobic treatment.Abbreviations HRT hydraulic retention time - OD₅₄₆ optical density at 546 nm     

黄孢原毛皮革菌降解苯胺的工艺研究

通过正交试验优化筛选了适合黄孢原毛皮革菌降解苯胺的适宜培养基和摇瓶培养降解条件。结果表明：其适宜降解的液体培养基组成为：蔗糖20g／L,可溶性淀粉20g／L,(NH4)2SO4l0g／L,Mn^2 lμmol／L,Tween-800．3％,蛋白胨30g／L。适宜降解的摇瓶培养条件为：接种量为20％、pH为7．0、温度为30℃、培养时间为12d．此条件下的苯胺最高降解率可达95．5％。     

Hydroxylase activity of immobilized haemoglobin

Until now, hydroxylation of substrates for practical applications has been mostly carried out by chemical and microbial processes. The hydroxylase activity of haemoglobin could be of great help for this purpose. Hydroxylation of aniline by haemoglobin immobilized as cross-linked soluble polymers and insoluble particles was studied. Activity yields after immobilization as well as kinetic constants were estimated. Hydroxylase activities similar to those of liver microsomal cytochrome P-450 activities were obtained.     

Characterization of isofunctional ring-cleaving enzymes in aniline and 3-chloroaniline degradation by Pseudomonas acidovorans CA28

During degradation of aniline and 3-chloroaniline, respectively, by Pseudomonas acidovorans CA28, selective induction of two catechol 1,2-dioxygenases (C12O) was observed. C12O I activity was the sole ring-cleaving enzyme detectable in cell-free extracts after growth on aniline, while C12O II was exclusively found after growth on 3-chloroaniline. Both enzymes were clearly differentiated by their elution behaviour on DEAE-cellulose and their substrate specificities. For C12O I high activity was demonstrable only with unsubstituted catechol, while C12O II showed preference for and high affinity towards chlorinated catechols. Therefore, evidence of different ortho-cleavage enzymes in Pseudomonas acidovorans CA28 involved in aniline and 3-chloroaniline metabolism, respectively, is indicated.     

Adsorption of phenol and aniline on natural and organically modified montmorillonite: experiment and molecular modelling

Natural and intercalated Wyoming montmorillonite (MMT) with the tetramethylammonium (TMA) cations were used for the adsorption of phenol and aniline. Laboratory experiments characterised by adsorption isotherms were compared with the results of molecular modelling simulations. Aniline adsorbed itself strongly on MMT; while using the TMA intercalates (TMA-MMT), its adsorption decreased. On the contrary, the adsorption of phenol on TMA-MMT was moderately higher than on the MMT surface. The MMT surface models were described by empirical force field used in molecular mechanics and dynamics. The Burchart–Universal force field was used in the Cerius² modelling environment. The modelling results revealed the important role of water forming a moderately concentrated layer on the pure MMT surface. Water molecules enable the adsorption of aniline on MMT and, on the contrary, repel phenol molecules from MMT. In the case of TMA-MMT, lower amount of water near a silicate layer caused decrease in the aniline adsorption and, on the contrary, increase in the phenol adsorption.