LACTATE AND GLUCOSE OXIDATION SYSTEMS IN ACETOBACTER SUBOXYDANS

1. From a strain of Acetobacter suboxydans, a glucose and a lacticenzyme were obtained in cell-free states. The lactic enzymeshows as strong activity as the glucose enzyme but is more stablethan the latter toward various purification procedures: bothare sensitive to high temperature treatment. Activities of thetwo enzymes and the MICHAELIS constants of the glucose enzymewere determined under both aerobic and anaerobic conditions.
2. Carbon monoxide inhibits the oxygen-uptake in both glucoseandlactate oxidation. WARBURG's distribution constant for lactateoxidation is 6.7. These results suggest the participation ofan heme enzyme in the oxidation system.
3. Effects of copperreagents, narcotics and PCMB were also examined.
4. The dehydrogenaseactivities (reduction of dye) of the enzymesare more sensitiveto high temperature than the correspondingactivities in oxygen-uptake.
5. By combining a dehydrogenase preparation which has lost itsoxygen-absorbing activity through acetone treatment, with aheated extract, a partial recovery of oxygen-uptake can be realizedin lactate oxidation.
6. L-Cysteine is utilized as hydrogen donorby the bacterium. Thisoxidative reaction, unlike the oxidationof lactate, is notinhibited by surface active reagents.

(Received May 16, 1960; )     

A new method in growth-electrophysiology: Pressurized intra-organ perfusion

Abstract A new experimental system was devised for the simultaneous measurement of elongation rate and the activity of the spatially separate electrogenic ion pumps of a hypocotyl segment excised from a seedling of Vigna unguiculata L. Walp. under enforced intra-organ perfusion by artificial solutions. The pathway of the perfusion medium was apoplastic space, including xylem vessels as main routes. The elongation rate of the segment was highly dependent on the perfusion pressure applied. It was possible to increase the growth rate under pressurized perfusion by 10-30 times as much as that without perfusion. Elongation rate was also dependent on respiration under perfusion, being retarded reversibly by anoxia a few minutes after the activities of the electrogenic ion pumps were stopped. Perfusion pressure had a little influence on the membrane potential (V_px) below a breakdown level (c. 130 kPa). Perfusion of mannitol or sorbitol solution of appropriate concentration reduced the elongation rate reversibly.     

DEMONSTRATION OF ALKALINE PHOSPHATASE PARTICIPATION IN THE MINERALIZATION OF OSTEOBLASTS BY ANTISENSE RNA APPROACH

MC3T3-E1 cells grown with ascorbic acid express sequentially osteoblastic marker proteins such as alkaline phosphatase (ALPase) and then form a mineralized extracellular matrix (ECM) as a consequence of osteoblastic differentiation. To explore the functional roles of ALPase in the process of osteoblastic maturation, an inducible expression vector for antisense ALPase RNA was constructed and stably transfected into MC3T3-E1 cells. The expression of antisense ALPase RNA in the differentiated MC3T3-E1 transfectants reduced markedly the ALPase activity, which resulted in a significant decrease in the deposition of minerals upon prolonged culture. These findings demonstrated directly that ALPase participated in the mineralizationof ECM.     

Mass mortality of Japanese macaques in a western coastal forest of Yakushima

The mass mortality of wild Japanese macaques (Macaca fuscata Blyth) was observed in a warm temperate forest of Yakushima, southern Japan. Demographic changes of eight troops between August 1998 and August 1999 were studied and 56% of macaques disappeared from the five intensively studied troops. Mortality varied among troops: two troops became extinct, while another troop did not decrease in size. The rate of mortality of the other troops was between 33 and 80%. The variation in mortality among the troops was either the outcome of local concentrations of mortality or of intertroop competition. The rate of mortality decreased with increasing distance from the two extinct troops and with increasing troop size; these two factors could not be separated statistically. The direct cause of death was diagnosed as pneumonia for four out of five fresh carcasses. The fleshy fruit production in autumn 1998 was the lowest in 14years, and macaques had relied on leaves earlier than in usual years. It was exceptionally hot and dry in the summer of 1998. The exceptionally poor fruit production and hot summer of this year, with the resulting shortage of high-quality foods, was consistent with the scenario that mass mortality was due to the poor nutritional conditions. However, the possibility that epidemics caused the mass mortality cannot be ruled out. Our findings proved that primates in a seemingly stable habitat experience fluctuations in demographic parameters under natural conditions.     

ENDOGENOUS CHANGES OF PHOTOCHEMICAL ACTIVITIES OF SPINACH LEAVES

The activities of green cell-free extracts of spinach leavesin performing photochemical transphosphorylation, photosyntheticphosphorylation, the HILL reaction and the light-induced formationof the endogenous reducing substance (ascorbic acid) were followedin parallel during the growth process of the plant. There wasa certain parallelism between the development of the activitiesof photochemical transphosphorylation, of photo-synthetic phosphorylationand of the HILL reaction, activities being low in the earlierstage of growth, reaching a maximum just before efflorescence,and showing thereafter a more or less sharp decline. The activityin the light-induced formation of endogenous reducing substancewas undetectable for the first 35 day-period of growth, reacheda maximum about one week earlier than the other three activities,and again disappeared after 60 days of growth. (Received September 9, 1960; )     

COMPONENTS OF THE ELECTRON-TRANSFERRING SYSTEM IN ACETOBACTER SUBOXYDANS AND RECONSTRUCTION OF THE LACTATE OXIDATION SYSTEM

1. Cytochromes a₁⁵⁹⁰, b⁵⁶⁰, c₁⁵⁵⁴ and c₁⁵⁵² were isolated andpurifiedfrom a strain of Acetobacter suboxydans. The proceduresusedwere described in detail.
2. The main cytochrome band at550-560 mµ in intact cellssplitted at liquid air temperatureinto two bands, 551 mµ(strong) and 559 mµ (weak).
3. Optical and physiological properties of the four cytochromeswere investigated. Lactic dehydrogenase activity was found tobe associated with cytochrome c₁⁵⁵⁴. The two c₁-type cytochromes,especially cytochrome c₁⁵⁵⁴, persisted in their reduced formafter the purification through many steps.
4. By some combinationsof isolated components reconstruction ofthe oxygen uptake systemcould be realized.
5. The oxygen-consuming activity of purifiedoxidase preparationswas accelerated by a-tocopherol but notby Emasoll 4130 andTween 80.
6. Some discussions were made onthe nature of terminal oxidase,the role of cytochrome c₁⁵⁵²in the electron-transport system,and persistence of reducedstate of c₁-type cytochromes.
7. A possible scheme of the electron-transferringsystem of Acetobactersuboxydans was presented.

(Received May 16, 1960; )     

Patapius spinosus: First record of Leptopodidae (Heteroptera) from Japan

Patapius spinosus, a remarkable leptopodid bug whose body is covered with spines, was collected for the first time in Japan. This species was found in the supralittoral zone of a sandy beach in Osaka Prefecture, central Japan, in autumn 2002 and in spring 2004. Patapius spinosus is known to be distributed in the Mediterranean and North African regions, and has been introduced into North America and Chile. Its occurrence in Japan could signify either an eastern limit of its native distribution or an exotic origin.     

三种兽药添加剂对土壤赤子爱胜蚓的毒理学研究

喹乙醇、阿散酸和土霉素是应用极广的兽药添加剂,在畜牧业的发展中起着特殊的作用,但其使用不当或过量使用会给环境带来很大危害.采用土壤中的重要生物赤子爱胜蚓作为生物材料,分别研究了喹乙醇、阿散酸和土霉素对赤子爱胜蚓的急性毒性和对赤子爱胜蚓体腔细胞DNA的损伤.结果表明,喹乙醇溶液法LC₅₀>2000mg·L^-1,滤纸法LC₅₀>5.71×10^-2mg·cm^-2,而阿散酸和土霉素在所设最大受试剂量内没有毒性.单细胞凝胶电泳试验结果表明,阿散酸没有引起蚯蚓体腔细胞DNA明显损伤;喹乙醇和土霉素均能引起一定程度的DNA损伤,中、高剂量组与阴性对照相比有极显著差异(P<0.01).因此,有必要加强对以上兽药添加剂,特别是喹乙醇和土霉素的管理,控制用药时间和剂量,以确保人体健康和环境安全.