Bacillus thuringiensis: A Common Member of Microflora in Activated Sludges of a Sewage Treatment Plant

Bacillus thuringiensis was recovered at a high frequency from activated-sludge system environments in an urban sewage-digestive plant. All of the test materials, sampled at several digesting steps, contained the organism. Of 515 colonies belonging to the B. cereus/B. thuringiensis group, 45 (8.7%) were assigned to B. thuringiensis. The highest density of this bacterium was 1.6 × 10³ cfu/ml in a scum sample of the first aeration basin. Among the 45 isolates, 7 were assigned to the known H serovars. Two isolates of the serovar kenyae isolates exhibited Lepidoptera-specific toxicity. Diptera-specific toxicity was shown by an isolate of serovar israelensis and a serologically undefined isolate. Lectin activity was associated with 12 isolates. Received: 10 October 2000 / Accepted: 17 November 2001     

Preventive effect of 20(S)-ginsenoside Rg3 against lipopolysaccharide-induced hepatic and renal injury in rats

The preventive effect of 20(S)-ginsenoside Rg₃ (20(S)-Rg₃) on lipopolysaccharide (LPS)-induced oxidative tissue injury in rats was investigated in this study. The elevated serum nitrite/nitrate, glutamic oxaloacetic transaminase, glutamic pyruvic transaminase and creatinine levels in LPS-treated control rats were significantly decreased following 15 consecutive days of 20(S)-Rg₃ administration. In addition, thiobarbituric acid-reactive substance levels in the serum, liver and kidney were dose-dependently lower in 20(S)-Rg₃-treated groups than in the LPS-treated control group. The nuclear factor-κB (NF-κB), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS) and heme oxygenase-1 (HO-1) protein expressions in the liver and kidney were significantly increased by LPS treatment. However, the 20(S)-Rg₃ administrations significantly decreased these protein expressions except for HO-1 in the liver. On the other hand, in the kidney, oral administration of 20(S)-Rg₃ showed a tendency to reduce NF-κB and iNOS protein expressions and also significantly reduced the elevated COX-2 and HO-1 protein expressions at a dose of 10 mg/kg body weight/day. All these results suggest the preventive effect of 20(S)-Rg₃ against LPS-induced acute oxidative damage in the liver and kidney and the preventive effect of 20(S)-Rg₃ administration against LPS toxicity was thought to be more predominant in the liver than kidney.     

Lipids and Lipoprotein Complex in Photosynthetic Tissues

The lipids and pigments of corn and soybean leaves grown in light and in dark were examined. The green leaf contained appreciably greater amounts of the two galactolipids, sulfolipid, phosphatidyl glycerol and diphosphatidyl glycerol, while the etiolated leaf had relatively more cerebroside, sterol glucoside, phosphatidyl ethanolamine and lecithin. The prominent component of glycerides was 1,2-diglyceride in green leaf, and triglyceride in etiolated leaf. The green leaf lipids showed a remarkable specificity of component fatty acids, but those of etiolated leaf only at lower rate. From the results, possible functions of the lipids were discussed.     

Identification of Indole Derivatives as Self-Growth Inhibitors of Symbiobacterium thermophilum, a Unique Bacterium Whose Growth Depends on Coculture with a Bacillus sp.

Symbiobacterium thermophilum is a syntrophic bacterium whose growth depends on coculture with a Bacillus sp. Recently, we discovered that CO₂ generated by Bacillus is the major inducer for the growth of S. thermophilum; however, the evidence suggested that an additional element is required for its full growth. Here, we studied the self-growth-inhibitory substances produced by S. thermophilum. We succeeded in purifying two substances from an ether extract of the culture supernatant of S. thermophilum by multiple steps of reverse-phase chromatography. Electron ionization mass spectrometry and nuclear magnetic resonance analyses of the purified preparation identified the substances as 2,2-bis(3′-indolyl)indoxyl (BII) and 1,1-bis(3′-indolyl)ethane (BIE). The pure growth of S. thermophilum was inhibited by authentic BII and BIE with MICs of 12 and 7 μg/ml, respectively; however, its growth in coculture with Bacillus was not inhibited by BII at the saturation concentration and was inhibited by BIE with an MIC of 14 μg/ml. Both BII and BIE inhibited the growth of other microorganisms. Unexpectedly, the accumulation levels of both BII and BIE in the pure culture of S. thermophilum were far lower than the MICs (<0.1 μg/ml) while a marked amount of BIE (6 to 7 μg/ml) equivalent to the MIC had accumulated in the coculture. An exogenous supply of surfactin alleviated the sensitivities of several BIE-sensitive bacteria against BIE. The results suggest that Bacillus benefits S. thermophilum by detoxifying BII and BIE in the coculture. A similar mechanism may underlie mutualistic relationships between different microorganisms.     

Bilirubin exhibits a novel anti-cancer effect on human adenocarcinoma

Anti-oxidants are essential for intracellular free radical scavenging, as free radicals are one of the causes for tumorigenesis. Our objective was to use bilirubin and investigate its action on human carcinoma cell lines. Bilirubin manifested as a prooxidant showing its cytopathic effect on TMK-1, showing growth inhibition close to 50%. Cell cycle analysis showed an arrest at G0/G1. Flow cytometry investigations with Red CC-1 showed an increase by more than 2 times suggesting a prooxidative role of bilirubin. To check the effect of radicals on DNA, a Comet Assay displayed a typical comet's tail with bilirubin treated slides, only. Further, staining with DAPI showed apoptotic action of bilirubin. Decreased mitochondrial function by bilirubin was observed with Mitotracker Green FM staining. These unexpected data have led us to conclude that bilirubin has anti-cancer activity as a prooxidant and may have a more vital role in the human body than realized.     

Transthyretin deposition promotes progression of osteoarthritis

Deposition of amyloid is a common aging‐associated phenomenon in several aging‐related diseases. Osteoarthritis (OA) is the most prevalent joint disease, and aging is its major risk factor. Transthyretin (TTR) is an amyloidogenic protein that is deposited in aging and OA‐affected human cartilage and promotes inflammatory and catabolic responses in cultured chondrocytes. Here, we investigated the role of TTR in vivo using transgenic mice overexpressing wild‐type human TTR (hTTR‐TG). Although TTR protein was detected in cartilage in hTTR‐TG mice, the TTR transgene was highly overexpressed in liver, but not in chondrocytes. OA was surgically induced by destabilizing the medial meniscus (DMM) in hTTR‐TG mice, wild‐type mice of the same strain (WT), and mice lacking endogenous Ttr genes. In the DMM model, both cartilage and synovitis histological scores were significantly increased in hTTR‐TG mice. Further, spontaneous degradation and OA‐like changes in cartilage and synovium developed in 18‐month‐old hTTR mice. Expression of cartilage catabolic (Adamts4, Mmp13) and inflammatory genes (Nos2, Il6) was significantly elevated in cartilage from 6‐month‐old hTTR‐TG mice compared with WT mice as was the level of phospho‐NF‐κB p65. Intra‐articular injection of aggregated TTR in WT mice increased synovitis and significantly increased expression of inflammatory genes in synovium. These findings are the first to show that TTR deposition increases disease severity in the murine DMM and aging model of OA.