Removal of Phenolic and Lignin Compounds from Bleached Kraft Mill Effluent by Fly Ash and Sepiolite

This study aimed to remove phenolic and lignin compounds from paper mill industry (4500 m³/h) wastewaters, which is discharged to sea from a plant located in the western Turkey. As adsorbent, fly ash, raw sepiolite and heat-activated sepiolite were used. The effect of factors such as, particle size, temperature and pH on adsorption process was investigated. From kinetic studies, equilibrium time was found as 1 h for both. The kinetic data supports pseudo-second order model but shows very poor fit for pseudo-first order model. Intraparticle model also shows that there are two separate stages in sorption process, namely, external diffusion and pore diffusion. Adsorption isotherms for fly ash and activated sepiolite were obtained at two different temperatures. From experiments carried out at different pHs, it was observed that pH plays an important role in the adsorption process in removing of both lignin and phenolic compounds, providing both ionizating the compounds and modifying sorbent surfaces. It was also observed that heat-activated sepiolite is more effective than raw sepiolite and fly ash to remove these compounds. Adsorption of lignin and phenolic compounds increases with decreasing particle size. In addition, the efficiency of adsorption decreases with increasing adsorption temperature for both fly ash and untreated sepiolite.     

Recovery of Kraft Lignin from Aqueous Solutions with Oxotitanium Sulfate,Aluminum Sulfate,and Their Mixture

Coagulation recovery of kraft lignin from aqueous solutions with oxotitanium sulfate, aluminum sulfate, and a composite coagulant based on their mixture was studied in a wide range of coagulant concentrations and solution pH values.     

Enzymatic synthesis of triglycerides catalyzed by lipases fromPenicillium sp.

Two lipases have been isolated from Penicillium sp.and purified. A synthetase activity of the total lipase preparation has been shown in an aqueous medium and in a system of reversed micelles (RMs) of a surfaceactive agent (SAA) in benzene, and advantages of the reversed-micelle system over an aqueous medium have been demonstrated. Institute of Microbiology, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 41 71 29. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 122–126, January-February, 1995. Original article submitted October 14, 1994.     

Biomass Photochemistry. V. Modifications of Lignin by Photochemical Treatment and Its Chemiluminescence

Lignin modifications resulting from different photochemical pre-treatments were studied using chemiluminescent methods. In the oxidation of lignin in NaOH solutions at 25°C, the intensity increased with increasing temperature and can be described by an Arrheniustype exponential equation with an activation energy of 25.8 ± 2.7 kJ/ mol. The oxidation of lignin model compounds under these conditions indicated ¹O₂ OH′, and O₂ generation. Chemiluminescence of the luminol/H₂O₂/Fe²⁺ system was used to study decomposition products of lignin upon irradiation. Unirradiated lignin proved to be an excellent radical trap, an effect initially abolished upon irradiation. At longer irradiation times, however, the radical trapping behavior was restored. The action of the perodidase/H₂ O₂ system onlignin was also investigated using chemiluminescence. Behavior very similar to that using luninol was observed. The intensity increases with increasing time of irradiation up to an optimum value. More prolonged irradiation results in total quenching of the cheiluminescemce. This is indicative of depolymerization and posterior aggregation.     

Enzymatic hydrolysis of alpha- and beta-oligo(L-aspartic acid)s by poly(aspartic acid) hydrolases-1 and 2 from Sphingomonas sp. KT-1

The enzymatic hydrolysis of alpha- and beta-oligo(L-aspartic acid)s by PAA hydrolase-1 and PAA hydrolase-2 (purified from Sphingomonas sp. KT-1) was performed to elucidate the mechanism of the microbial degradation by Sphingomonas sp. KT-1 of the thermally synthesized alpha,beta-poly(D,L-aspartic acid) (tPAA). GPC analysis of the hydrolyzed products of alpha- and beta-tetra(L-aspartic acid)s by PAA hydrolase-1 has showed that PAA hydrolase-1 is capable of hydrolyzing only the specific amide bonds between beta-aspartic acid units. The RP-HPLC analysis of the enzymatic hydrolysis of beta-oligo(L-aspartic acid)s (4 and 5 mers) by PAA hydrolase-1 has suggested that the enzymatic hydrolysis of beta-oligo(L-aspartic acid)s occurs via an endo-mode cleavage. In contrast, PAA hydrolase-2 hydrolyzed both alpha- and beta-oligo(L-aspartic acid)s via an exo-mode cleavage to yield L-aspartic acid as a final product. A kinetic study on the enzymatic hydrolysis of alpha-oligo(L-aspartic acid)s (3 to 7 mers) by PAA hydrolase-2 has indicated that Km values are almost independent of the number of monomer units in oligomers of 4 to 7 mers, while that Vmax values are markedly dependent on the chain length and show a maximum value at 5 mer.     

Citrinal A,a novel tricyclic derivative of citrinin,from an algicolous fungus Penicillium sp.i-1-1

Citrinal A(1),a novel tricyclic compound with a rare tetrahydro-2H-benzofuro[7-b][1,4]dioxin-9(3H)-one skeleton,along with two known related compounds,citrinin(2) and 2,3,4-trimethyl-5,7-dihydroxy-2,3-dihydrobenzofuran(3) were isolated from an algicolous fungus Penicillium sp.i-1-1.The structure and stereochemistry of 1 were determined by comprehensive spectral and biogenic analysis.Its cytotoxic effects on the A-549 and HL-60 cell lines were evaluated.     

Ubiquinone Q9 from a marine isolate of an actinobacterium Nocardia sp.

The major component of a nonpolar fraction of an extract of an actinobacterium Nocardia sp. KMM 3749 isolated from an unidentified marine ascidian was shown, using NMR spectroscopy and mass spectrometry, to be 2,3-dimethoxy-5-methyl-6-polyprenyl-1,4-benzoquinone (ubiquinone Q₉).     

海洋芽孢杆菌酯酶BSE-1的催化动力学和热失活动力学研究

海洋芽孢杆菌发酵产生的酯酶BSE-1经分离纯化后,以对硝基苯磷酸酯(PNPP)为底物,对电泳纯BSE-1的催化性质、催化动力学和热失活动力学进行了研究.催化动力学研究表明,金属离子对BSE-1的活性影响显著,其中Ca2 的激活作用最强,为混合型激活作用;而Ba2 的抑制作用最为明显,为非竞争性抑制作用.BSE-1的酶促反应动力学符合米氏方程,其中Km=8.15mmol·L-1,Vmax=0.97mmol·mg-1·min-1.采用连续模型对BSE-1在70℃的热失活动力学进行模拟,求得酶的失活速率常数k1=1.41,k2=0.28.     

Activation of P5R5 (R = Ph, Et) by a Rh-beta-diketiminate complex

(NacNac)Rh(C8H14))(N2) reacts with P5R5 to give complexes of formula (NacNac)Rh(P5R5) (R = Ph, Et); in the former species inversion of a P atom of P5Ph5 allows coordination to a Rh(I) centre, whereas in the later species a P-P bond undergoes oxidative addition to give a formally Rh(III) species.     

Preparative Isolation and Purification of Altertoxin I from an Alternaria sp. by HSCCC

Altertoxin I (ATX I) is one of the common mycotoxins produced by genus Alternaria which is a common food pathogen of fruits and grains. To prepare enough quantity of pure ATX I for further research of mutagenicity and toxicology tests, a novel method using preparative high-speed counter-current chromatography (HSCCC) was developed. The ethyl acetate crude extracts of the acetone washes obtained after fermentation of Alternaria sp. was separated using a two-phase solvent system composed of n-hexane–ethyl acetate–methanol–water (2:5:5:6, v/v). Collected fractions were analyzed by LC and identified by EI–MS and NMR analysis. The technique can isolate mg levels of the target compound per run.

     

Preparative Isolation and Purification of Altertoxin I from an Alternaria sp. by HSCCC

Altertoxin I (ATX I) is one of the common mycotoxins produced by genus Alternaria which is a common food pathogen of fruits and grains. To prepare enough quantity of pure ATX I for further research of mutagenicity and toxicology tests, a novel method using preparative high-speed counter-current chromatography (HSCCC) was developed. The ethyl acetate crude extracts of the acetone washes obtained after fermentation of Alternaria sp. was separated using a two-phase solvent system composed of n-hexane–ethyl acetate–methanol–water (2:5:5:6, v/v). Collected fractions were analyzed by LC and identified by EI–MS and NMR analysis. The technique can isolate mg levels of the target compound per run.     

Chemical investigation of metabolites produced by an endophytic Aspergillus sp. isolated from Limonia acidissima

Endophytic fungi are considered as a good source to produce important secondary metabolites with interesting bioactivities. In a continuation of our studies towards the search for environmentally friendly bioactive compounds from Sri Lankan flora, we investigated the secondary metabolites produced by the endophytic fungi Aspergillus sp. isolated from the seeds of the popular edible fruit Limonia acidissima L. of the family Rutaceae. The pure culture of the Aspergillus sp. was grown on potato dextrose broth media. After 4 weeks fermentation, fungal media were extracted with organic solvents. Chromatographic separation of the fungal extracts over silica gel, Sephadex LH-20 and RP-HPLC furnished flavasperone (1), rubrofusarin B (2), aurasperone A (3), fonsecinone D (4) and aurasperone B (5). Compounds 1–4 showed moderate activities in brine shrimp toxicity assay. This is the first report of the ¹³C NMR data of compounds 4 and 5.     

Asperphenyltones A and B: New Phenylfuropyridinone Skeleton from an Endophytic Aspergillus sp. GXNU-A1

Chemical investigation of the fermentation extract of the mangrove endophytic fungus Aspergillus sp. GXNU-A1, isolated from Acanthus ilicifolius L., discovered an undescribed pair of enantiomers (asperphenyltones A and B (±1)), together with four previously described metabolites: nodulisporol (2), isosclerone (3), 2,3,4-trihydroxy-6-(hydroxymethyl)-5-methylbenzyl alcohol (4), and 4,6-dihydroxy-5-methoxy-7-methyl-1,3-dihydroisobenzofuran (5). Analyses of the 1D and 2D NMR spectroscopic data of the compounds supported their structural assignments. The presence of the asperphenyltones A and B, which are a pair of enantiomers, was established by HR-ESI-MS, 1D and 2D NMR data and confirmed by single-crystal X-ray diffraction analysis. Metabolites 1–5 were evaluated for their anti-inflammatory effects on the production of nitric oxide (NO), and 1, 3, and 4 showed significant potential inhibitory activities against NO production in activated macrophages with IC₅₀ values of 26–40 μM, respectively.     

PTP1B Inhibitory Secondary Metabolites from an Antarctic Fungal Strain Acremonium sp. SF-7394

Chemical investigation of the Antarctic lichen-derived fungal strain Acremonium sp. SF-7394 yielded a new amphilectane-type diterpene, acrepseudoterin (1), and a new acorane-type sesquiterpene glycoside, isocordycepoloside A (2). In addition, three known fungal metabolites, (−)-ternatin (3), [D-Leu]-ternatin (4), and pseurotin A (5), were isolated from the EtOAc extract of the fungal strain. Their structures were mainly elucidated by analyzing their NMR and MS data. The absolute configuration of 1 was proposed by electronic circular dichroism calculations, and the absolute configuration of the sugar unit in 2 was determined by a chemical method. The inhibitory effects of the isolated compounds on protein tyrosine phosphatase 1B (PTP1B) were evaluated by enzymatic assays; results indicated that acrepseudoterin (1) and [D-Leu]-ternatin (4) dose-dependently inhibited the enzyme activity with IC₅₀ values of 22.8 ± 1.1 μM and 14.8 ± 0.3 μM, respectively. Moreover, compound 1 was identified as a competitive inhibitor of PTP1B.     

Effectiveness of Sal Deoiled Seed Cake as an Inducer for Protease Production from Aeromonas sp. S1 for its Application in Kitchen Wastewater Treatment

The present study is an attempt to demonstrate the feasibility of sal (Shorea robusta) deoiled cake—a forest-based industrial by-product—as a cheaper media supplement for augmented protease production from Aeromonas sp. S1 and application of protease in the treatment of kitchen wastewater. Under optimized conditions, protease production could successfully be enhanced to 5.13-fold (527.5 U mL^?1) on using sal deoiled seed cake extract (SDOCE), as medium additive, compared to an initial production of 102.7 U mL^?1 in its absence. The culture parameters for optimum production of protease were determined to be incubation time (48 h), pH (7.0), SDOCE concentration (3 % (v/v)), inoculum size (0.3–0.6 % (v/v)), and agitation rate (100 rpm). The enzyme was found to have an optimum pH and temperature of 8.0 and 60 °C, respectively. The protease preparation was tested for treatment of organic-laden kitchen wastewater. After 96 h of wastewater treatment under static condition, enzyme preparation was able to reduce 74 % biological oxygen demand, 37 % total suspended solids, and 41 % oil and grease. The higher and improved level of protease obtained using sal deoiled seed cake-based media hence offers a new approach for value addition to this underutilized biomass through industrial enzyme production. The protease produced using this biomass could also be used as pretreatment tool for remediation of organic-rich food wastewater.     

Isolation and characterization of an exopolygalacturonase from Fusarium oxysporum f.sp. cubense race 1 and race 4

Background

Previously, we have reported the presence of highly sulfated dermatans in solitary ascidians from the orders Phlebobranchia (Phallusia nigra) and Stolidobranchia (Halocynthia pyriformis and Styela plicata). Despite the identical disaccharide backbone, consisting of [→4IdoA(2S)β-1→3GalNAcβ-1→], those polymers differ in the position of sulfation on the N-Acetyl galactosamine, which can occur at carbon 4 or 6. We have shown that position rather than degree of sulfation is important for heparin cofactor II activity. As a consequence, 2,4- and 2,6-sulfated dermatans have high and low heparin cofactor II activities, respectively. In the present study we extended the disaccharide analysis of ascidian dermatan sulfates to additional species of the orders Stolidobranchia (Herdmania pallida, Halocynthia roretzi) and Phlebobranchia (Ciona intestinalis), aiming to investigate how sulfation evolved within Tunicata. In addition, we analysed how heparin cofactor II activity responds to dermatan sulfates containing different proportions of 2,6- or 2,4-disulfated units.

Results

Disaccharide analyses indicated a high content of disulfated disaccharide units in the dermatan sulfates from both orders. However, the degree of sulfation decreased from Stolidobranchia to Phlebobranchia. While 76% of the disaccharide units in dermatan sulfates from stolidobranch ascidians are disulfated, 53% of disulfated disaccharides are found in dermatan sulfates from phlebobranch ascidians. Besides this notable difference in the sulfation degree, dermatan sulfates from phlebobranch ascidians contain mainly 2,6-sulfated disaccharides whereas dermatan sulfate from the stolidobranch ascidians contain mostly 2,4-sulfated disaccharides, suggesting that the biosynthesis of dermatan sulfates might be differently regulated during tunicates evolution. Changes in the position of sulfation on N-acetylgalactosamine in the disaccharide [→4IdoA(2-Sulfate)β-1→3GalNAcβ-1→] modulate heparin cofactor II activity of dermatan sulfate polymers. Thus, high and low heparin cofactor II stimulating activity is observed in 2,4-sulfated dermatan sulfates and 2,6-sulfated dermatan sulfates, respectively, confirming the clear correlation between the anticoagulant activities of dermatan sulfates and the presence of 2,4-sulfated units.

Conclusions

Our results indicate that in ascidian dermatan sulfates the position of sulfation on the GalNAc in the disaccharide [→4IdoA(2S)β-1→3GalNAcβ-1→] is directly related to the taxon and that the 6-O sulfation is a novelty apparently restricted to the Phlebobranchia. We also show that the increased content of [→4IdoA(2S)β-1→3GalNAc(4S)β-1→] disaccharide units in dermatan sulfates from Stolidobranchia accounts for the increased heparin cofactor II stimulating activity.     

Biotransformation of Chloro-Substituted Indoles to Indigoids by Phenol Hydroxylase from Arthrobacter sp. W1

Recombinant Escherichia coli cells expressing phenol hydroxylase (designated as strain PH_IND) were used to synthesize chloro-substituted indigoids by the transformation of indoles. The optimal conditions for the biotransformation of 4- and 7-chloroindole were determined by response surface methodology. Biotransformation kinetic assays revealed that strain PH_IND showed high catalytic efficiency for 4- and 7-chloroindole. The formation rate of 7,7′-dichloroindigo (1.35 unit/mg cell dry weight) by strain PH_IND was 1.14-fold higher than that of 4,4′-dichloroindigo. The intermediates of 7-chloroindole biotransformation were identified by high-performance liquid chromatography–mass spectroscopy, and the biotransformation mechanism was also proposed. These results suggested that there was a potential application of strain PH_IND in the biotransformation of chloro-substituted indoles to valuable indigoids.