Influence of some trace metals and stimulants on citric acid production from brewery wastes by Aspergillus niger

The addition of increasing levels of Mn²⁺, Fe³⁺, Zn²⁺, Co²⁺, Cu²⁺, Ca²⁺, sodium monofluoracetate and methanol during citric acid surface fermentation of spent grain liquor by Aspergillus niger (ATCC 9142) was investigated. For spent grain liquor the addition of 51 ppb Mn²⁺, 5 ppb Fe³⁺, 75 ppb Zn²⁺ and 4% (v/va) methanol caused a 4.9, 1.9, 10.9 and 16.8% increase in citric acid yield respectively. In all other fermentations the yield of citric acid was decreased whereas the biomass production in some cases was increased.     

Effect of manganese on ninhydrin color development by amino acids

Addition of microgram quantities (5–10 μg per 2 ml) of Mn²⁺, Fe²⁺, and Mo²⁺ increases the intensity of color developed by amino acids two- to three-fold when reacting with ninhydrin. The lowest limit detected by the increased sensitivity of the reaction is 3 nmol of an amino acid. Cd²⁺, Zn²⁺, and Al³⁺ depress the color formation due to reaction between amino acids and ninhydrin. When chromatograms of amino acids are first sprayed with aqueous manganese chloride and later with ninhydrin or with ninhydrin solution containing manganese, not only is the sensitivity increased, but the stained spots retain their color for longer periods.     

Activated carbon-containing alginate adsorbent for the simultaneous removal of heavy metals and toxic organics

By combining two functions of alginate gel and activated carbon, an activated carbon-containing alginate bead (AC-AB) adsorbent was developed and successfully used to simultaneously remove heavy metal ions and toxic organics. Quantitative analysis showed that almost all of the adsorption of toxic organics, such as p-toluic acid, is caused by the activated carbon in the AC-AB adsorbent, whereas the alginate component has a major role in the removal of heavy metals. A 50-L solution containing eight heavy metals (Pb²⁺, Mn²⁺, Cd²⁺, Cu²⁺, Zn²⁺, Fe²⁺, Al³⁺ and Hg²⁺) and four mineral ions was run continuously through a filter cartridge packed with 160 g of the AC-AB adsorbent. The adsorbent showed a high capacity to remove heavy metals completely from the water, while allowing essential minerals, such as K⁺, Na⁺, Mg²⁺ and Ca²⁺, to pass through the filter. The adsorbent could be regenerated using eluents, such as HNO₃, and reused repeatedly without considerable loss of its metal uptake capacity through 10 subsequent cycles of adsorption and desorption. With its high capacity and high selectivity for toxic heavy metals, the AC-AB adsorbent has enormous potential for application in drinking water treatment technologies.     

Effects of Metals on 3-Acetyldeoxynivalenol Production by Fusarium graminearum R2118 in Submerged Cultures

The effects of selected metals (Mg²⁺, Mn²⁺, Zn²⁺, and Fe²⁺) on 3-acetyldeoxynivalenol (3-ADN) production by Fusarium graminearum R2118 and on its mycelial growth were investigated by using a two-stage submerged-culture technique. In certain concentrations ranges, Mg²⁺ and Fe²⁺ stimulated growth but suppressed 3-ADN production; at other concentrations, Mg²⁺, Fe²⁺, and Zn²⁺ suppressed growth but stimulated 3-ADN production. In contrast, Mn²⁺ stimulated growth but totally inhibited 3-ADN production at all concentrations tested. In general, the production of 3-ADN was inversely related to the growth rate of the fungus with these metals. Mn²⁺ appears to be a crucial factor regulating the onset of 3-ADN biosynthesis.     

Heavy metal ions affect the activity of DNA glycosylases of the Fpg family

Prokaryotic enzymes formamidopyrimidine-DNA glycosylase (Fpg) and endonuclease VIII (Nei) and their eukaryotic homologs NEIL1, NEIL2, and NEIL3 define the Fpg family of DNA glycosylases, which initiate the process of repair of oxidized DNA bases. The repair of oxidative DNA lesions is known to be impaired in vivo in the presence of ions of some heavy metals. We have studied the effect of salts of several alkaline earth and transition metals on the activity of Fpg-family DNA glycosylases in the reaction of excision of 5,6-dihydrouracil, a typical DNA oxidation product. The reaction catalyzed by NEIL1 was characterized by values K _m = 150 nM and k _cat = 1.2 min⁻¹, which were in the range of these constants for excision of other damaged bases by this enzyme. NEIL1 was inhibited by Al³⁺, Ni²⁺, Co²⁺, Cd²⁺, Cu²⁺, Zn²⁺, and Fe²⁺ in Tris-HCl buffer and by Cd²⁺, Zn²⁺, Cu²⁺, and Fe²⁺ in potassium phosphate buffer. Fpg and Nei, the prokaryotic homologs of NEIL1, were inhibited by the same metal ions as NEIL1. The values of I₅₀ for NEIL1 inhibition were 7 μM for Cd²⁺, 16 μM for Zn²⁺, and 400 μM for Cu²⁺. The inhibition of NEIL1 by Cd²⁺, Zn²⁺, and Cu²⁺ was at least partly due to the formation of metal-DNA complexes. In the case of Cd²⁺ and Cu²⁺, which preferentially bind to DNA bases rather than phosphates, the presence of metal ions caused the enzyme to lose the ability for preferential binding to damaged DNA. Therefore, the inhibition of NEIL1 activity in removal of oxidative lesions by heavy metal ions may be a reason for their comutagenicity under oxidative stress.     

Effects of heavy metals on pollen tube growth and ultrastructure

Summary The influence of different concentrations of the heavy metals cadmium (Cd²⁺), cobalt (Co²⁺), copper (Cu²⁺), iron (Fe²⁺ and Fe³⁺), mercury (Hg²⁺), manganese (Mn²⁺), and zinc (Zn²⁺), plus aluminium (Al³⁺) (a toxic metal in polluted areas), on pollen germination and tube growth ofLilium longiflorum was investigated using light microscopy. Effects could be observed with 3 M and 100 M of heavy metal, added as chloride salts to the medium. Cd²⁺, Cu²⁺, and Hg²⁺, showed the greatest toxicity, whereas germination and growth rate was less affected by Mn²⁺. Affected tubes showed swelling of the tip region. Tubes treated with Cd²⁺, Co²⁺, Fe²⁺, Fe³⁺, Hg²⁺, and Mn²⁺ were also prepared for ultrastructural studies. In all cases, the main effect was abnormal cell wall organization, mostly at the tip, where round, fibrillar aggregates, the shape and size of secretory Golgi vesicles were formed. They built up a loose network which could be up to 10 m thick compared to untreated tubes where the cell wall was composed of thin layers of long fibrils and about 100 nm thick. Cd²⁺ was the only metal which produced effects at the intracellular level: organelle distribution within the tip region appeared disorganized. A general mechanism of heavy metal action on pollen tube growth is discussed.     

Effect of Fe2+, Mn2+, Zn2+ and Pb2+ on H+/K+ fluxes in excisedPistia stratiotes roots

Pistia stratiotes is used for the epuration of domestic sewage in the Biyem Assi phytopurification station. During the process, Fe²⁺, Mn²⁺, Zn²⁺ and Pb²⁺ are absorbed in substantial amounts by the plant. These metals modify the H⁺/K⁺ exchange system at the root level. H⁺ efflux is inhibited by Fe²⁺ and by Zn²⁺ and enhanced by Mn²⁺ and Pb²⁺. K⁺ influx is inhibited by Fe²⁺, by Zn²⁺ and by Pb²⁺ and enhanced by Mn²⁺. It is shown that the purification capacity ofPistia stratiotes can vary with the composition of the heavy metals in the surrounding medium.     

不同浓度Fe2+与Zn2+对羊草幼苗生长和生理特性的影响

以羊草幼苗为研究对象,通过调整全营养培养基(CK,0.05 mmol/L Fe²⁺、0.015 mmol/L Zn²⁺)中铁或者锌含量设置0、10倍、20倍Fe²⁺(Zn²⁺)浓度处理Fe₀(Zn₀)、Fe₁₀(Zn₁₀)、Fe₂₀(Zn₂₀),以及在高铁培养基中单独添加0.15 mmol/L Zn²⁺或同时添加10 mmol/L Ca²⁺、5 mmol/L Mg²⁺、20 mmol/L K⁺处理,测定培养6 d后幼苗生长指标和矿质元素含量、以及高铁(Fe₂₀)处理下幼苗根中抗氧化指标和相关基因表达量,探究不同浓度Fe²⁺、Zn²⁺对羊草幼苗生长、矿质元素吸收积累及抗氧化指标、基因表达的影响。结果表明：(1)缺锌(Zn₀)显著抑制羊草幼苗鲜重的增加和Zn元素的积累,但促进Fe、Mg元素的积累;高浓度锌(Zn₁₀、Zn₂₀)显著促进幼苗叶片生长和Zn元素的积累;缺铁(Fe₀)显著抑制幼苗的根长、鲜重和Fe元素的积累,促进Mg、Zn元素的积累;高浓度铁(Fe₁₀、Fe₂₀)显著抑制羊草幼苗根叶生长、根毛发育和Ca、Zn、Mg、K元素的积累。(2)增加Zn²⁺和Ca²⁺、Mg²⁺、K⁺浓度无法恢复高铁胁迫对幼苗生长的抑制作用。(3)高浓度铁(Fe₂₀)处理羊草幼苗48 h后,根部过氧化物酶、超氧化物歧化酶、过氧化氢酶、抗坏血酸过氧化物酶、谷胱甘肽还原酶活性和丙二醛、抗坏血酸、还原型谷胱甘肽含量显著升高;烟酰胺合成酶基因、过氧化物酶基因表达量显著下调,植物类萌发素蛋白基因表达量显著上调。研究发现,羊草幼苗生长发育和矿质元素积累对环境中Zn²⁺浓度变化不敏感,却受到环境中高浓度Fe²⁺的显著抑制,并造成严重的氧化胁迫伤害,这种伤害无法在添加Zn²⁺或同时添加Ca²⁺、Mg²⁺、K⁺的条件下恢复。     

Inhibition of Na+/K+-ATPase and Mg2+-ATPase by metal ions and prevention and recovery of inhibited activities by chelators

Kinetics and inhibition of Na⁺/K⁺-ATPase and Mg²⁺-ATPase activity from rat synaptic plasma membrane (SPM), by separate and simultaneous exposure to transition (Cu²⁺, Zn²⁺, Fe²⁺ and.Co²⁺) and heavy metals (Hg²⁺and Pb²⁺) ions were studied. All investigated metals produced a larger maximum inhibition of Na⁺/K⁺-ATPase than Mg²⁺-ATPase activity. The free concentrations of the key species (inhibitor, MgATP^{2 ?} , MeATP^{2 ?} ) in the medium assay were calculated and discussed. Simultaneous exposure to the combinations Cu²⁺/Fe²⁺ or Hg²⁺/Pb²⁺caused additive inhibition, while Cu²⁺/Zn²⁺ or Fe²⁺/Zn²⁺ inhibited Na⁺/K⁺-ATPase activity synergistically (i.e., greater than the sum metal-induced inhibition assayed separately). Simultaneous exposure to Cu²⁺/Fe²⁺ or Cu²⁺/Zn²⁺ inhibited Mg²⁺-ATPase activity synergistically, while Hg²⁺/Pb²⁺ or Fe²⁺/Zn²⁺ induced antagonistic inhibition of this enzyme. Kinetic analysis showed that all investigated metals inhibited Na⁺/K⁺-ATPase activity by reducing the maximum velocities (V_max) rather than the apparent affinity (K_m) for substrate MgATP^2-, implying the noncompetitive nature of the inhibition. The incomplete inhibition of Mg²⁺-ATPase activity by Zn²⁺, Fe²⁺ and Co²⁺ as well as kinetic analysis indicated two distinct Mg²⁺-ATPase subtypes activated in the presence of low and high MgATP^{2 ?} concentration. EDTA, L-cysteine and gluthathione (GSH) prevented metal ion-induced inhibition of Na⁺/K⁺-ATPase with various potencies. Furthermore, these ligands also reversed Na⁺/K⁺-ATPase activity inhibited by transition metals in a concentration-dependent manner, but a recovery effect by any ligand on Hg²⁺-induced inhibition was not obtained.     

Inhibitory effects of some natural products on metal-induced lipid oxidation in cooked fish

Divalent metal ions (Fe²⁺, Cu²⁺, Zn²⁺, Ni²⁺, and Mn²⁺) induced lipid oxidation in cooked, but not in raw fish. The extent of lipid oxidation, measured by the production of thiobarbituric acid reactive substances (TBRS), was increased with higher concentrations of iron, zinc, and nickel, but was decreased with increasing concentrations of copper and manganese. The natural products: ellagic acid, tannic acid, myricetin, and quercetin, inhibited lipid oxidation in cooked fish. The enhanced lipid oxidation caused by cupric ions (10³ pmol/100 g fish) was also inhibited by the natural products. The degree of inhibition in copper-treated fish, however, was less than that in fish that had no added copper. The inhibition was concentration dependent. The antioxidative potency of the various natural products was independent of the type of metal ion-induced lipid oxidation. Ellagic acid was the most potent antioxidant (75.7–83.9%), followed by tannic acid (60.4–77.3%), myricetin (52.9–70.4%), and quercetin (32.6–44.2%).     

Nutritional factors regulating growth and accumulation of phenazine 1-carboxylic acid by Pseudomonas fluorescens 2-79

Summary Pseudomonas fluorescens strain 2-79 (NRRL B-15 132) is a biocontrol agent of take-all of wheat caused by the fungus Gaeumannomyces graminis var. tritici. Strain 2-79 produces the antibiotic phenazine 1-carboxylic acid, which acts as the primary mechanism of disease suppression. As a first step toward designing efficient methods of mass producing and formulating this biocontrol agent, the regulation of growth and antibiotic production by growth factors (including purines, pyrimidines, vitamins) and minerals (supplying B³⁺, Ca²⁺, Co²⁺, Cu²⁺, Fe²⁺, Mg²⁺, Mn²⁺, Mo⁶⁺, Zn²⁺) was examined in defined liquid culture. Additions of boric acid and sulfates of iron and magnesium enhanced both cell and associated antibiotic accumulation. However, accumulation of the antibiotic alone improved with additions of zinc sulfate, ammonium molybdate, and cytosine, but worsened with addition of adenine. Interactive effects involving the sulfates of iron, magnesium, and zinc were observed, and optimal iron-magnesium and iron-zinc combinations were demonstrated with respect to biomass and antibiotic accumulation, respectively.The mention of firm names or trade products does not imply that they are endorsed or recommended by the U. S. Department of Agriculture over other firms or similar products not mentioned Correspondence to: P. J. Slininger     

Role of Organic Acids in Sunflower Tolerance to Heavy Metals

Exposure of Helianthus annuus L. seedlings to Al³⁺, Cd²⁺ or Zn²⁺ resulted in a marked decrease of fresh and dry masses of the shoots and the roots. The increase of Al³⁺, Cd²⁺ or Zn²⁺ uptake was accompanied by a significant decrease of nitrate, phosphorus and K⁺ uptake. There was a significant increase of malic and citric acid contents in the shoots and roots of heavy metal-treated seedlings whereas the change in fumaric acid was insignificant. Al³⁺ and Zn²⁺ alone stimulated excretion of malic and citric acids to the rhizosphere. Addition of high concentrations of malic or citric acid alleviate to some extent the inhibitory effect of Al³⁺ and Zn²⁺ on plant growth. This revised version was published online in July 2006 with corrections to the Cover Date.     

Combined actions of Pb2+, Zn2+, and Al3+ on voltage-activated calcium channel currents

Summary 1. Whole-cell patch clamp experiments were performed on rat dorsal root ganglion (DRG) neurons to investigate the actions of various combinations of Pb²⁺, Zn²⁺, and Al³⁺ on voltage-activated calcium channel currents (VACCCs).2. Each of these metals has been shown to reduce VACCCs.3. We investigated the effects of simultaneous application of two cations in the range of their IC₅₀ values. For all possible combinations (Pb²⁺/Zu²⁺, Zn²⁺/Al³⁺, Al³⁺/Pb²⁺), independent of the order of application, we found additive actions on VACCCs.4. We observed a 75% (±9%) block of the control current when two cations were applied simultaneously. This observation is consistent with both, an action of two metals at the same site as well as independent actions at different locations of the ion channel.5. The additivity of the effects should be taken into account for questions of public health and the assessment of threshold limits in cases of environmental contamination.     

Fluorescent sensors based on BODIPY derivatives for aluminium ion recognition: an experimental and theoretical study

Two BODIPY derivative sensors for metal ion recognition containing 10-(4-hydroxyphenyl) (L1) and 10-(3,4-dihydroxyphenyl) (L2) were synthesized in a one-pot reaction of benzaldehyde derivative and 2,4-dimethylpyrrole in the presence of trifluoroacetic acid as catalyst. The binding abilities between these sensors and 50 equivalents of Na⁺, K⁺, Ag⁺, Ca²⁺, Fe²⁺, Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺, Cd²⁺, Pb²⁺, Al³⁺ and Cr³⁺ ions were studied using UV–vis and fluorescent spectroscopic methods. Of all the metal ions tested, Al³⁺ ion showed the greatest decrease in intensity in the spectra of the sensors, and therefore Al³⁺ ion forms the strongest complex. The binding abilities of BODIPY receptors with Na⁺, Ag⁺, Ca²⁺, Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺ and Al³⁺ ions were also investigated using density functional theory (DFT) calculations at B3LYP/LanL2DZ theoretical level. The calculated results point to the same conclusion. DFT calculations also provided the HOMO–LUMO energy levels, which can explain the spectrum change upon complexation.

Inhibition of the biosynthesis ofN-acetylneuraminic acid by metal ions and seleniumin vitro

In liver homogenate the biosynthesis ofN-acetylneuraminic acid usingN-acetylglucosamine as precursor can be followed stepwise by applying different chromatographic procedures. In this cell-free system 16 metal ions (Zn²⁺, Mn²⁺, La³⁺, Co²⁺, Cu²⁺, Hg²⁺, VO ₃ ^– , Pb²⁺, Ce³⁺, Cd²⁺, Fe²⁺, Fe³⁺, Al³⁺, Sn²⁺, Cs⁺ and Li⁺) and the selenium compounds, selenium(IV) oxide and sodium selenite, have been checked with respect to their ability to influence a single or possible several steps of the biosynthesis ofN-acetylneuraminic acid. It could be shown that the following enzymes are sensitive to these metal ions (usually applied at a concentration of 1 mmoll^–1):N-acetylglucosamine kinase (inhibited by Zn²⁺ and vandate), UDP-N-acetylglucosamine-2-epimerase (inhibited by zn²⁺, Co²⁺, Cu²⁺, Hg²⁺, VO ₃ ^– , Pb²⁺, Cd²⁺, Fe³⁺, Cs⁺, Li⁺, selenium(IV) oxide and selenite), andN-acetylmannosamine kinase (inhibited by Zn²⁺, Cu²⁺, Cd²⁺, and Co²⁺). Dose dependent measurements have shown that Zn²⁺, Cu²⁺ and selenite are more efficient inhibitors of UDP-N-acetylglucosamine-2-epimerase than vanadate. As for theN-acetylmannosamine kinase inhibition, a decreasing inhibitory effect exists in the following order Zn²⁺, Cd²⁺, Co²⁺ and Cu²⁺. In contrast, La³⁺, Al³⁺ and Mn²⁺ (1 mmoll^–1) did not interfere with the biosynthesis ofN-acetylneuraminic acid. Thus, the conclusion that the inhibitory effect of the metal ions investigated cannot be regarded as simply unspecific is justified.Dedicated to Professor Theodor Günther on the occasion of his 60th birthday     

The effect of amphotericin B on the permeability of lipid bilayers to divalent trace metals

In this study amphotericin B released the divalent trace metals Zn²⁺, Co²⁺, Cu²⁺, Ni²⁺, Mn²⁺, Fe²⁺, Cd²⁺ and Pb²⁺ from multilamellar liposomes containing cholesterol. This observation is consistent with amphotericin B channels being permeable to these metals, and it is proposed, therefore, that the antibiotic may be useful in investigating the metabolism of these elements.     

Influence of Trace Elements Mixture on Bacterial Diversity and Fermentation Characteristics of Liquid Diet Fermented with Probiotics under Air-Tight Condition

Cu²⁺, Zn²⁺, Fe²⁺ and I⁻ are often supplemented to the diet of suckling and early weaning piglets, but little information is available regarding the effects of different Cu²⁺, Zn²⁺, Fe²⁺ and I⁻ mixtures on bacteria growth, diversity and fermentation characteristics of fermented liquid diet for piglets. Pyrosequencing was performed to investigate the effect of Cu²⁺, Zn²⁺, Fe²⁺ and I⁻ mixtures on the diversity, growth and fermentation characteristics of bacteria in the liquid diet fermented with Bacillus subtilis and Enterococcus faecalis under air-tight condition. Results showed that the mixtures of Cu²⁺, Zn²⁺, Fe²⁺ and I⁻ at different concentrations promoted Bacillus growth, increased bacterial diversity and lactic acid production and lowered pH to about 5. The importance of Cu²⁺, Zn²⁺, Fe²⁺ and I⁻ is different for Bacillus growth with the order Zn²⁺> Fe²⁺>Cu²⁺> I⁻ in a 21-d fermentation and Cu²⁺>I⁻>Fe²⁺>Zn²⁺ in a 42-d fermentation. Cu²⁺, Zn²⁺, Fe²⁺ and I⁻ is recommended at a level of 150, 60, 150 and 0.6 mg/kg respectively for the production of fermented liquid diet with Bacillus subtilis. The findings improve our understanding of the influence of trace elements on liquid diet fermentation with probiotics and support the proper use of trace elements in the production of fermented liquid diet for piglets.     

Elemental metals as electron sources for biological methane formation from CO2

Several elemental metals were examined as potential electron donors for methanogenic bacteria, using both a single tube system where the metal was in direct contact with the cells, and a two-flask system, where metal and cells were not in direct contact, but had contact via the gas phase. With all organisms examined in the direct contact system, Fe^o, Al^o and Zn^o served as electron donors for methanogenesis; some organisms used Ni^o or Sn^o as low-level electron donors. Of the metals tested, methanogenesis from H₂+CO₂ was inhibited by direct contact with Zn^o or Cu^o, but not by Fe^o or Al^o. Ni^o and Co^o were inhibitory to some methanogens, with Ni^o being particularly inhibitory to the thermophilic strains tested. With all organisms examined in the two-flask system, Fe^o and Zn^o served as good electron sources for both methanogenesis and growth; Co^o generated a very low level of methane and Cu^o did not work at all. In either system V^o, Ti^o or Cd^o did not serve as electron donors. The results suggest that some elemental metals (notably Fe^o, Al^o and Zn^o) produce gaseous H₂ by cathodic depolarization which is then consumed by the methanogen, thus accelerating oxidation of the metal by its metabolic activity. All of these reactions are thermodynamically favorable; however, some other metals that are clearly favorable for such a reaction on thermodynamic grounds (Ti^o and V^o) are very stable and do not serve as electron donors.Preliminary results on this topic were presented at the Pan American Biodeterioration Society Meeting in Washington, D.C. July 28–31, 1988.     

Yersiniabactin metal binding characterization and removal of nickel from industrial wastewater

Yersiniabactin (Ybt) is a metal‐binding natural product that has been re‐purposed for water treatment. The early focus of this study was the characterization of metal binding breadth attributed to Ybt. Using LC‐MS analysis of water samples exposed to aqueous and surface‐localized Ybt, quantitative assessment of binding was completed with metals that included Pd²⁺, Mg²⁺, and Zn²⁺. In total, Ybt showed affinity for 10 metals. Next, Ybt‐modified XAD‐16N resin (Ybt‐XAD) was utilized to quantify the affinity for metal removal, showing a rank order of Fe³⁺ > Ga³⁺ > Ni²⁺ > Cu²⁺ > Cr²⁺≈Zn²⁺ > Co²⁺ > Pd²⁺ > Mg²⁺ > Al³⁺, and in the applied treatment of wastewater from a local precious metal plating company, showing selective removal of nickel from the aqueous effluent. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:1548–1554, 2017     

Influence of metal addition on ethanol production with <Emphasis Type="Italic">Pichia stipitis</Emphasis> ATCC 58784

Trace metals always act as cofactors or coenzymes in many cellular processes. Deficiency or excess of some metals will affect the fermentation of lignocellulosic hydrolysate. In order to make sure the deficient or excessive states of metals in culture medium, metal contents analysis was conducted in Pichia stipitis ATCC 58784 cells, synthetic medium, and diluted acid hydrolysate of rice straw. The results showed that Cu, Ni, and Co were deficient, and Al was a little excessive. So the influences of Cu²⁺, Al³⁺, Ni²⁺, and Co²⁺ additions on the growth and ethanol production of ATCC 58784 were further researched. Low concentration additions of Cu²⁺ and Al³⁺ (<0.24 mM and <0.23 mM, respectively) improved biomass growth of ATCC 58784 by 34 and 13%, respectively; however, higher concentrations decreased biomass growth. On the other hand, addition of Cu²⁺ (0.39 mM) did not affect volumetric ethanol production significantly (P = 0.05) and addition of Al³⁺ (0.38 mM) showed no influence on volumetric ethanol production (P = 0.68). Addition of 0.074 mM Co²⁺ inhibited biomass growth of ATCC 58784 by 13% and volumetric ethanol production by 10%. The biomass growth and volumetric ethanol production of ATCC 58784 was arrested by the addition of 0.33 mM of Ni²⁺ by 53 and 65%, respectively.