• Journal of Microbiology and Biotechnology
• /
• 제21권2호
• /
• pp.136-146
• /
• 2011

This study provides first-hand proteomic data on the survival strategy of Anabaena sp. PCC 7120 when subjected to long-term iron-starvation conditions. 2D-gel electrophoresis followed by MALDI-TOF/MS analysis of iron-deficient Anabaena revealed significant and reproducible alterations in ten proteins, of which six are associated with photosynthesis and respiration, three with the antioxidative defense system, and the last, hypothetical protein all1861, conceivably connected with iron homeostasis. Iron-starved Anabaena registered a reduction in growth, photosynthetic pigments, PSI, PSII, whole-chain electron transport, carbon and nitrogen fixation, and ATP and NADPH content. The kinetics of hypothetical protein all1861 expression, with no change in expression until day 3, maximum expression on the $7^{th}$ day, and a decline in expression from the $15^{th}$ day onward, coupled with in silico analysis, suggested its role in iron sequestration and homeostasis. Interestingly, the up-regulated FBP-aldolase, Mn/Fe-SOD, and all1861 all appear to assist the survival of Anabeana subjected to iron-starvation conditions. Furthermore, the $N_2$-fixation capabilities of the iron-starved Anabaena encourage us to recommend its application as a biofertilizer, particularly in iron-limited paddy soils.

• Asian-Australasian Journal of Animal Sciences
• /
• 제30권8호
• /
• pp.1160-1167
• /
• 2017

Objective: To assess the effects of proteinate complex zinc (PC-Zn) on growth performance, antioxidative function, trace element concentrations and immune function in weaned piglets. Methods: Three hundred newly weaned barrows ($Duroc{\times}Landrace{\times}Yorkshire$), 28 days of age, were randomly allotted to 3 dietary groups of 5 replicate pens per group for 4 weeks of feeding. Experimental diets were: i) zinc deficient diet (ZnD, 24 mg/kg Zn supplementation from $ZnSO_4$), ii) inorganic Zn diet supplemented with 120 mg/kg of Zn from Zn sulfate ($ZnSO_4$), and iii) organic Zn diet supplemented with 120 mg/kg of Zn from PC-Zn. The body weight of pigs were recorded at the beginning, at the middle and at the end of the experiment, and the amount of feed supplied each day was recorded. Five barrows from each dietary treatment group were selected to be anesthetized and euthanized at the end of the trial to determine the Zn, Cu, Fe, and Mn concentrations, the hepatic metallothionein content, the levels of methane dicarboxylic aldehyde (MDA), Mn, and Cu/Zn superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) in the spleen, the levels of interleukin (IL)-2, IL-4, IL-10, interferon $(IFN)-{\gamma}$, $CD3^+$, $CD4^+$, and $CD8^+$ T lymphocyte. Results: The accumulation of Zn in the spleen, levels of SOD, GSH-Px, IL-4, IL-10, the proportions of $CD3^+$ and $CD4^+$ T lymphocyte, and the ratio of $CD4^+/CD8^+$ T lymphocyte were increased by organic Zn supplementation compared to ZnD, while the levels of MDA, $IFN-{\gamma}$, and proportion of $CD8^+$ T lymphocyte were lowered. Conclusion: These findings indicate that Zn can improve the antioxidant potential and immune functions of weaned piglets.

• Molecules and Cells
• /
• 제23권3호
• /
• pp.370-378
• /
• 2007

A superoxide dismutase was purified 62-fold in seven steps to homogeneity from Methylobacillus sp. strain SK1, an obligate methanol-oxidizing bacterium, with a yield of 9.6%. The final specific activity was 4,831 units per milligram protein as determined by an assay based on a 50% decrease in the rate of cytochrome c reduction. The molecular weight of the native enzyme was estimated to be 44,000. Sodium dodecyl sulfate gel electrophoresis revealed two identical subunits of molecular weight 23,100. The isoelectric point of the purified enzyme was found to be 4.4. Maximum activity of the enzyme was measured at pH 8. The enzyme was stable at pH range from 6 to 8 and at high temperature. The enzyme showed an absorption peak at 280 nm with a shoulder at 292 nm. Hydrogen peroxide and sodium azide, but not sodium cyanide, was found to inhibit the purified enzyme. The enzyme activity in cell-free extracts prepared from cells grown in manganese-rich medium, however, was not inhibited by hydrogen peroxide but inhibited by sodium azide. The activity in cell extracts from cells grown in iron-rich medium was found to be highly sensitive to hydrogen peroxide and sodium azide. One mol of native enzyme was found to contain 1.1 g-atom of iron and 0.7 g-atom of manganese. The N-terminal amino acid sequence of the purified enzyme was Ala-Tyr-Thr-Leu-Pro-Pro-Leu-Asn-Tyr-Ala-Tyr. The superoxide dismutase of Methylobacillus sp. strain SK1 was found to have antigenic sites identical to those of Methylobacillus glycogenes enzyme. The enzyme, however, shared no antigenic sites with Mycobacterium sp. strain JC1, Methylovorus sp. strain SS1, Methylobacterium sp. strain SY1, and Methylosinus trichosproium enzymes.