Studies on the effect of environmental factors on the growth of 'nori' (Porphyra tenera KJELLM.), with special reference to the water current

The laver, Porphyra tenera, 'nori' in Japanese, is extensively cultivated in Japan, where dried laver, prepared in the form of thin sheets, is beloved as a delicacy and one of the most popular foods. In many coastal areas of the country, inhabitants earn important part of their livelihood by engaging in the culture industry of this seaweed. The laver farms are distributed along the Pacific coast, and generally located in bays and inlets, but especially in the Seto Inland Sea, they are limited to the estuaries at the mouths of rivers. The growth of laver is affected by such various environmental factors as water temperature, salinity, nutrient contents of sea water, etc. The author investigated into the reason why the laver farms in the Seto Inland Sea are located exclusively in estuaries by comparing the hydrographic conditions of these farms with those of the laver farms in Korea, in which country the laver farms are mostly located in those inshore waters where no stream empties. It was recognized through this investigation that, in the Seto Inland Sea, the growth oflaver is controlled by water currents no less than by water temperature and nutrient contents of water. The author then studied the effect and the optimal range of each of the important environmental factors by carrying out culture experiments mainly in the laboratory and partly in the field. The results of these studies are summarized below. (1) In the Seto Inland Sea, environmental conditions of the offshore waters are unsuitable for the growth of laver, because water temperature is relatively high (about l0°C in the winter or the peak season of laver's growth) as compared with the optimal temperature range for this seaweed (i.e., 6-10°C), and because the concentrations of nutrients in sea water are rather low and very changeable (Tables 1,3,4,5, and 6). In contrast, in estuarine waters, water temperature drops in the winter, water is rich in plant nutrients which are supplied by the river water, and moreover, water currents of favorable velocities are developed (Tables 7, 8, 9 and 10). It is in these waters that laver farms are located. (2) When water temperature is high, growth of laver is greatly affected by water current. Water currents transport nutrients to, and remove excreted metabolites from laver fronds. (3) In estuaries laver fronds are exposed to changing salinities. When laver fronds are experimentally exposed to a sudden change of salinity, their growth is accelerated if the time of exposure is very short (less than 15 min.), but retarded if exposure lasts longer (Table 12 and Text-fig. 3). (4) It was found, through the transplanting experiments from the Seto Inland Sea to Korea and between the localities in Korean waters, that laver is rather tolerant to the changes of environmental conditions (Tables 13 and 14). (5) The velocity of water current suitable for the growth of laver ranges from 15 to 30cm/sec, but the optimal velocity varies in relation to other environmental factors as well as the condition of laver frond (Table 17) as indicated below. (i) Optimal range of current velocity is narrow for young fronds, but becomes wider for older fronds (Table 17). When fronds are growing thick, they require rapid currents of velocities nearly 30 cm/sec (Tables 18 and 19). (ii) 7 cm/sec is the most suitable current velocity for the spores to attach. After attachment, however, growth is equally good within the velocity range from 7 to 25 cm/sec (Text-figs. 7 and 8). (iii) Rapid water currents have ill effects upon the growth of laver frond at low salinities; at the specific gravity (ρ15) of 1.018, optimal velocity is 20cm/sec (Table 20). (iv) Optimal current velocity for the growth oflaver varies very markedly according to the nutrient contents of sea water. It is about 20cm/sec in the ordinary sea water, but greater velocities (nearly 30cm/sec) are required if the concentrations of nutrients are lowered by diluting ordinary sea water with the NaCl solution of the same salinity. If ordinary sea water is enriched by adding nitrates and phosphates, water flow of 15cm/sec is sufficient for the best growth of laver. In the sea water enriched by adding ripe manure, laver fronds grow equally well over the velocity range from 5 to 20 cm/sec (Table 21). (v) At favorable temperatures (below 10°C), the range of suitable current velocity is wide (i.e., from 10 to 30cm/sec). When water temperature is relatively high (10-14°C), especially when nutrients are not available in sufficient amounts, rather rapid current (30cm/sec) is need. Laver fronds do not survive longer than 2 weeks at the water temperatures over 16oC (Text-fig. 9). (6) Growth of laver frond is affected also by light intensity. The growth increases with the increase of light intensity up to 10,000 lux, although the rate of the increase differs according to the light source (i.e., the spectrum of incident light). However, it seems that there exists an upper limit of suitable light intensity. This is inferred from the results of the growth experiment in which laver was cultured at different water depths throughout the growing season: the growth was best near the surface in December and January, but the zone of best growth moved downwards as the sun light became stronger with the further progress of the season (Tables 23, 24 and 25). (7) The roles that water current plays in controlling the growth of laver are considered on the basis of the results of various experiments. (i) As was shown in Section VII of the text and mentioned in summary (5) (iv), water current of nearly 30cm/sec is necessary for the maximum growth of laver frond if concentrations of plant nutrients are low in sea water, while a current only 5cm/sec is sufficient if the concentrations of nutrients are high. It seems therefore that the lower limit of the current velocity that is necessary for the maximum growth of the frond depends on the nutrient contents of sea water. On the other hand, it seems that there is an upper limit of current velocity which the laver frond can tolerate physiologically. Water currents faster than this limit do not have favorable effect upon the growth of the frond (Text-figs. 12 and 13). (ii) According to the results of the experiments in which laver fronds were cultured in the medium which presumably contained the external metabolites of this seaweed in excessive concentrations, it appears that the metabolic wastes of the laver, once liberated into the sea water, do not have any harmful effect upon the growth of the frond (Table 26). The culture medium employed in this experiment was the one in which laver fronds had been cultured in high densities; after these fronds were removed, the medium was enriched by adding nitrate and phosphate and used for the experiment. (iii) When laver fronds are cultured without renewing the culture medium, their growth is retarded. The harmful effect of such a culture condition is ascribable to the deficiency of plant nutrients, the rise of pH and the growth of bacteria and other microorganisms, rather than to the accumulation of laver's metabolic wastes. The rise of pH, which is particularly remarkable (Text-fig. 11), is probably due chiefly to the consumption of carbon dioxide as a result of photosynthesis rather than to alkaline substances which laver fronds may excrete (Table 29). (iv) It is concluded from the foregoing evidences that, from the viewpoint of the growth of laver, the major function of the water current is to transport dissolved plant nutrients to the fronds, that current velocities of 10-30cm/sec are needed for this function to be fulfilled, and that water currents of such velocities automatically accomplish such other beneficial functions as checking the rise of pH, removal of metabolic wastes, etc. (8) It was deduced from the foregoing results that in the Seto Inland Sea commercial laver culture need not be limited to estuarine waters and that other parts of the Sea can also be utilized as laver farms if there is suitable water current. In order to test the validity of this idea, laver culture was conducted on an experimental scale in the Onomichi Suido (Text-fig. 15) where the inflow of fresh water is very limited and commercial laver culture had never been attempted. According to our preliminary survey, the meteorological and hydrographic conditions of this strait did not appear unsuitable for the growth of laver. The results of this experimental culture indicated, as expected, that laver can be cultured commercially in this strait (Table 39). (9) The over-all results of the present study are presented in a condensed form in Table 40. This table shows how the variations in the four important environmental factors (i.e., water temperature, dissolved nutrients, illumination and water current) affect such qualities of the laver frond as color, luster, toughness, flavor, etc. In addition, the relative importances of these four environmental factors are evaluated from the viewpoint of the growth of laver fronds, and the result is expressed in the form of the ratio as below: water temperature : illumination : dissolved nutrients : water current = 30 : 10 : 35 : 25 or 35 : 10 : 35 : 20 It is hoped that this ratio, although it is a crude approximation, will serve as a guide when one tries to select sites suitable for laver culture

An optical system for measuring the eccentricity of glass wool pipe－for industrial use

An optical system for measuring the eccentricity of the glass wool pipe has been developed for an industrial use. The system consists of a contact sensor, a photo light sensor and a signal processing system with a logic circuit. The system is simple, fast and efficient for practical use; it allows implementation of on-line process monitoring and alarm warning signals for unacceptable pipe eccentricity during manufacturing

The repression of the reverse-oriented transcription from the adenovirus terminus by NFI in competition with TFIID

AbstractNuclear factor 1 (NFI) represses the transcription which is promoted by the cloned adenovirus (Ad) type 5 DNA replication origin and is reverse-oriented with respect to the direction of the replication. The mechanism of this repression by NFI was investigated. In the cell-free transcription system, the repression was observed only when NFI was present during the formation of the transcription initiation complex. From the results of DNase I protection experiments, it was indicated that NFI bound to its binding site in the Ad replication origin prevents TFIID from proper binding to the adjacent AT-rich region and consequently represses the transcription

A Case of Vascular Graft Infection Caused by Staphylococcus lugdunensis after Femoropopliteal Bypass Operation

A 79-year-old man who had undergone a right femoropopliteal (FP) bypass operation 6 weeks previously was diagnosed with vascular graft infection caused by Staphylococcus lugdunensis. Another FP bypass operation was performed, with long-term administration of antibiotics, and the patient eventually recovered well without any recurrences for over 2 years. Although S. lugdunens is classified as coagulase-negative Staphylococcus, its pathogenicity has been reported to be equal to that of S. aureus. Based on the literature review, the organism characteristically colonizes the inguinal area of human skin;thus, operations such as FP bypass grafting may place patients at a relatively high risk for infection by S. lugdunensis, a potentially high-pathogenicity organism

数種緑藻の遊離アミノ酸とペプチッド

7種の海産緑藻のエキスの遊離アミノ酸組成を調べた。その結果,アナアオサ(Ulva pertusa)にジペプチッド,L-arginyl-L-glutamineが著量に存在することを認めた。このペプチッドはイオン交換樹脂カラムクロマトグラフィーにより単離され,加水分解生成物の同定および合成によりその構造が確認された。アナアオサではL-arginyl-L-glutamineは全エキス窒素の約20%を占め,主成分をなしていた。さらにウスバアオノリ(Enteromorpha linza)にも検出されたが,外の5種には認められなかった。ウスバアオノリではarginyl-glutamineとともにprolineの含量が比較的高かった。この外,アサミドリシオグサ(Cladophora densa)ではglycineとproline,マユハキモ(Chlorodesmis comosa),ハイミル(Codium adhaerens)およびミル(Codium fragile)ではglutamic acidとglutamine,スリコギイワヅタ(Caulerpa racemosa)ではglycineの含量がそれぞれ高かった。 またこれら緑藻におけるアミノスルフォン酸の分布をペーパークロマトグラフィーにより調べた。その結果,taurineを4種の海藻に,D-cysteinolic acidを3種に,N-monomethyltaurineを2種に,homotaurineを1種にそれぞれ検出した。このうちアサミドリシオグサではhomotaurineを分離して確認した。The amino acid compositions of 7 marine green algal extracts were examined by means of an amino acid analyzer. Ulva pertusa was for the first time found to contain a dipeptide, L-arginyl-L-glutamine, in a large quantity. This peptide was detected also in Enteromorpha linza but not in the other five species. Glutamic acid and glutamine were relatively predominant in Codium fragile, C. adhaerens and Chlorodesmis comosa. In Caulerpa racemosa, the level of glycine was remarkably high. Glycine and proline were predominant in Cladophora densa. Aminosulfonic acids in these algae were examined by paper chromatography. Taurine was detected in 4 species, D-cysteinolic acid in 3, N-monomethyltaurine in 2, and homotaurine in 1, respectively. Occurrence of homotaurine in Cladophora densa was also established

35Sによるアサクサノリ及びアオサの硫黄の吸収に関する研究Ⅱ.

35Sを添加した海水中でアサクサノリを培養し，その葉体をFig. 1のように分割lし，各フラクションへの35Sの吸収を明暗両条件下で経時的に観察した. 1) 各フラクションの硫黄含量は培養期間 (24-48時間)中，ほとんど一定であった. 2) 35S の吸収は明条件下ではきわめて活発で，暗条件下では著しくにぶい.また明条件下の各フラクションの吸収状態は前報アオサの場合とほぼ同様の傾向を示した. 3) アルコール可溶部中の35S は大部分が陽イオン交換樹脂非吸着性の物質中に移った. 4) 陽イオン交換樹脂非吸着性物質のうちで35Sの存在を最も強く示しているものはタウリンであって，そのほか少量の未確認の物質にもみられ，また35SO4--のままのものも少量存在した. 5) 陽イオン交換樹脂非吸着性物質における35Sの所在について， ヒトエグサとオゴノリで実験した結果， ヒトエグサではDーシステノール酸に，オゴノリではアサクサノリと同じくタウリンに最も強く認められた.1. Sulfur contents of each fractions (ethanol soluble and insoluble, and hot water insoluble) of Porphyra tenera were almost stationary throughout the culture. 2. Aspects of sulfur uptake in various fractions of Porphyra tenera were as like as those of UIva pertusa. 3. Under light, sulfur uptake by Porphyra was very active, but under darkness it was very dull, particularly in ethanol insoluble fraction. 4. In Porphyra and Gracilaria, a considerable amount of 35S of the non-adsorbable was incorporated into taurine, while in Monostroma it was incorporated into Dcysteinolic acid

Studies on the sulfur uptake by porphyra tenera and ulva pertusa, using 35S

　アオサを35SO4，添加海水で、培養し熱水可溶，不溶， 80%アノレコール可溶，不容の各成分への硫黄の移行を時間的lこ追究した.またアサクサノリ及びアオサを同様に48時間培養し，同じく各成分への硫黄の移行を調べ，更にアノレコール可溶部分については， イオン交換樹脂を用いacidic，basic 及びneutral の3 fraction に分割し，各fraction における硫黄の動向について考察した. ① アオサでは硫黄の大部分は熱水可溶部及びその80% アノレコール不溶部にかなり短時間に入り24時間乃至48時間後lこはほぼ平衡に達する. ② 80%アノレコール可溶の部分ではやや異なり，培養開始後24時間までは比絞的緩慢であるが，その後はかなり大きく増加する. ③ アサクサノリ，アオサいずれも80%アルコール不溶の部分に多く吸収され， 80%アノレコール可容の部分ではアサクサノリの方がアオサに比して少い. ④ このfraction にはtaurine，cysteic acid， cysteinolic acid などのようなアミノスルフォン酸の存在が認められ，それらへの移行が考えられるが確認は出来なかった.The time-course of sulfur uptake and transferring to the fronds of Ulva pertusa was investigated, by means of culturing for I, 6, 12, 24 and 48 hours in the media added 35S04 • Distribution of sulfur and 35S-actiyity in the fronds were looked over from the fractions separated under the procedure of Text-fig. I. And also the sulfur uptake of Porphya tenera and of Ulva pertusa were compared, after the culturing for 48 hours with 35SO4 • The results are as follows. (1) 35S was taken rapidly into each fraction from the outset by Ulva pertusa and poised after 48 hours (see Table 1). (2) However, in the 80% ethanol soluble fraction, 35S-activity increased slowly at the beginning of culture, but after 24 hours, became faster. (3) Making a comparison between Porphyra tenera and Ulva pertusa, a good deal of 35S was taken up into the 80 % ethanol insoluble fractions of both, on the contrary, less activity was found in the 80 % ethanol soluble fraction of Porphyra tenera than Ulva pert usa (see Table 2). (4) In the latter fractions, there were found sulfonyl amino compounds such as taurine, cysteinolic acid or cysteic acid in either Porphyra tenera or Ulva pertusa. It is probable that 35 S-activity exists in these compounds

Low temperature formation of low resistivity W contact with ultra thin mixed layer on molecular layer epitaxially-grown GaAs

Proceedings of the IEEE 24th international symposium on compound semiconductors, San diego, California, 8-11 Semptember 199