Angelina's Advice....

'Agar agar' is a gelatinous substance derived from seaweeds. It has wide traditional culinary uses but has become an important part of the bacteriology lab as well.

Robert Koch is widely regarded as a pioneer of microbiology. He was the first to culture bacteria on the surface of a solid medium. Initially, he used a medium solidified with gelatin. But gelatin tended to melt at slightly higher temperatures and it was not possible to incubate the plates at a higher temperature. Furthermore, many bacteria were capable of attacking gelatin and degrading it. Walther Hesse, an assistant of Koch’s related his difficulties to his wife Angelina. Fanny Angelina Hesse suggested that he try an ingredient which her mother had given her. This ingredient was given to her mother by some friends in Java, Indonesia, who used it frequently in making fruit jams and jellies. This ingredient was called agar agar.

Walther Hesse substituted gelatin for agar agar and found it to give excellent results. Once solidified, agar agar was capable of resisting temperatures above 50 degrees Centigrade. He also found that very few bacteria were capable of degrading agar agar and thus it could serve as an excellent solidifying, yet inert, agent. He conveyed his results to Robert Koch who used agar plates to isolate Mycobacterium tuberculosis. He published his results on 24th March 1882.

From then on, agar plates were widely used the world over for cultivating and isolating bacteria. They are also used to aseptically grow tissue-cultured plants or calluses. Agar agar has been used in Japanese culinary practices as a thickener for making jellies, custards and puddings. Some popular Japanese recipes that use agar are anmitsu and mizuyokan. Agar has also gained popularity (or notoriety) as a new get-slim diet known as the “kanten diet.”

Technically, Agar (China Grass, kanten or Japanese isinglass) is a polysaccharide made up of repeating galactose units. It is an unbranched polysaccharide obtained from cell walls of red algae like Gracilaria or Gelidium or from the seaweed, Sphaerococcus euchema. Commercially, however, it is obtained from Gelidium amansii. Agar agar has been used as a laxative, thickener in soups, jams, jellies and in traditional Japanese desserts. It is also used as a clarifier in brewing industries. Agar agar is also widely used to treat constipation. But studies have revealed that long term use of agar agar as a laxative for chronic constipation can lead to bowel obstruction and esophageal obstruction. It reduces absorption of vitamins, minerals and other nutrients.

Ref: Wolfgang Hesse, (Translatedby Dieter H.M. Groschel), Walther and Angelina Hesse early contributors to bacteriology, ASM news, Vol 58, No.88, 1992. Pg 425-428.

The "missing Nobel Laureate"

Mohandas Gandhi (1869-1948) has become the strongest symbol of non-violence in the 20th century. It is widely held – in retrospect – that the Indian national leader should have been the very man to be selected for the Nobel Peace Prize. He was nominated several times, but was never awarded the prize. Why?

These questions have been asked frequently: Was the horizon of the Norwegian Nobel Committee too narrow? Were the committee members unable to appreciate the struggle for freedom among non-European peoples?" Or were the Norwegian committee members perhaps afraid to make a prize award which might be detrimental to the relationship between their own country and Great Britain?

Gandhi was nominated in 1937, 1938, 1939, 1947 and, finally, a few days before he was murdered in January 1948. The omission has been publicly regretted by later members of the Nobel Committee; when the Dalai Lama was awarded the Peace Prize in 1989, the chairman of the committee said that this was "in part a tribute to the memory of Mahatma Gandhi". However, the committee has never commented on the speculations as to why Gandhi was not awarded the prize, and until recently the sources which might shed some light on the matter were unavailable.

Why was Gandhi never awarded the Nobel Peace prize?

Up to 1960, the Nobel Peace Prize was awarded almost exclusively to Europeans and Americans. In retrospect, the horizon of the Norwegian Nobel Committee may seem too narrow. Gandhi was very different from earlier Laureates. He was no real politician or proponent of international law, not primarily a humanitarian relief worker and not an organiser of international peace congresses. He would have belonged to a new breed of Laureates.

There is no hint in the archives that the Norwegian Nobel Committee ever took into consideration the possibility of an adverse British reaction to an award to Gandhi. Thus it seems that the hypothesis that the Committee's omission of Gandhi was due to its members' not wanting to provoke British authorities, may be rejected.

In 1947 the conflict between India and Pakistan and Gandhi's prayer-meeting statement, which made people wonder whether he was about to abandon his consistent pacifism, seem to have been the primary reasons why he was not selected by the committee's majority. Unlike the situation today, there was no tradition for the Norwegian Nobel Committee to try to use the Peace Prize as a stimulus for peaceful settlement of regional conflicts.

During the last months of his life, Gandhi worked hard to end the violence between Hindus and Muslims which followed the partition of India. We know little about the Norwegian Nobel Committee's discussions on Gandhi's candidature in 1948 – other than the above quoted entry of November 18 in Gunnar Jahn's diary – but it seems clear that they seriously considered a posthumous award. When the committee, for formal reasons, ended up not making such an award, they decided to reserve the prize, and then, one year later, not to spend the prize money for 1948 at all. What many thought should have been Mahatma Gandhi's place on the list of Laureates was silently but respectfully left open. 

Courtesy: Nobel prize.org

Mullis murmur...

"Sometimes a good idea comes to you when you are not looking for it. Through an improbable combination of coincidences, naiveté and lucky mistakes, such a revelation came to me one Friday night in April, 1983, as I gripped the steering wheel of my car and snaked along a moonlit mountain road into northern California’s redwood country. That was how I stumbled across a process that could make unlimited numbers of copies of genes, a process now known as the polymerase chain reaction (PCR)"

Kary B. Mullis,

Scientific American (1990) 262:36.

Silvia said...

"When I come to the laboratory of my father, I usually see some plates lying on the tables. These plates contain colonies of bacteria. These colonies remind me of a city with many inhabitants. In each bacterium there is a king. He is very long, but skinny. The king has many servants. These are thick and short, almost like balls. My father calls the king DNA, and the servants-enzymes... My father has discovered a servant who serves as a pair of scissors. If a foreign king invades a bacterium, this servant can cut him in small fragments, but he does not do any harm to his own king."

- Silvia (when 10 years old), 

daughter of Werner Arber, a Nobel Laureate (who shared the honor with Daniel Nathans and Hamilton O. Smith for the discovery of restriction enzymes and their application to molecular genetics).

Silvia Arber is now a professor of neurobiology at the University of Basel, studying neuronal circuit formation in the developing spinal cord. She is a recipient of the prestigious Latsis prize in the year 2003. The prize, comes with a cheque of SFr100, 000 ($75,100), is awarded annually by Switzerland’s National Science Foundation, aimed at encouraging young researchers.

Hyping up science

Science when hyped loses credibility. Two separate incidents in a span of three weeks show how scientists who hype up and sensationalise their work end up diluting the significance of their discovery. In a paper published online in the Science journal in the first week of December 2010 (“A bacterium that can grow by using arsenic instead of phosphorus” by Felisa Wolfe-Simon, et al), authors from the National Aeronautics and Space Administration (NASA) and other institutions report that a particular bacterium isolated from California's Mono Lake was capable of substituting arsenic for a small percentage of phosphorus and still sustain its growth. This is a most surprising finding considering that arsenic is a toxic element and is not one of the six elements - carbon, oxygen, hydrogen, nitrogen, sulphur, and phosphorus - that make up most of the organic molecules in living matter. Days before publication of the paper, the worldwide web went wild with speculation about extra-terrestrial life. The reason: a media advisory sent out by NASA on a press briefing “to discuss an astrobiology finding that will impact the search for extra-terrestrial life.” In consequence, most media reports following the publication of the paper dwelt on the issue of extra-terrestrial life. It turned out that the paper did not discuss the possibility of life outside Earth; nor did the accompanying news item published in the journal propose anything of the kind.

The second instance of hyping up science relates to a press release from Tel Aviv University. According to this, the earliest evidence of existence of modern humans has been found in Israel, predating evidence found in Africa by about 200,000 years. The conclusion contradicts the prevailing view of human evolution and migration out of Africa. What followed was sensationalist media coverage of an otherwise stodgy work of purely academic interest. The paper, which reports the morphological analysis of human teeth recovered from Israel's Qesem Cave, was recently published online in The American Journal of Physical Anthropology (“Middle Pleistocene dental remains from Qesem Cave [Israel]” by Israel Hershkovitz et al). The paper says the teeth cannot be conclusively identified as belonging to modern humans (Homo sapiens) or to Neanderthals or to other human species. While the journalists can be faulted for oversimplifying and hyping up the findings of science, the deliberate misleading of the media and the public by some scientists and their institutions must be condemned. Such acts by a few take a heavy toll on the credibility of science.

Source: The Hindu dated Jan 13, 2011, Thursday.