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Life comes full Circle

Professor Hanna Engelberg-Kulka

This woman's father was refused a job at Vienna University in 1939. Now she's been awarded an honorary doctorate . . . from the same educational establishment

How's this for irony? In 1939, as the scourge of Nazism worsened, a young Jewish doctor was refused a staff position in chemistry at the University of Vienna.

Skip forward 76 years to May 2015 when, in recognition of her groundbreaking work in microbiology, that man's daughter was awarded an honorary doctorate – from the same university.

She is Professor Hanna Engelberg-Kulka, of the Department of Microbiology and Molecular Genetics at the Hebrew University-Hadassah Faculty of Medicine. Fortunately, her father's university rejection led to his decision to emigrate to Palestine that year with his young family.

In contrast, his brother – who was convinced that the size of Poland's Jewish community was enough to guarantee his safety – moved there from Vienna and met with a tragic fate.

Hanna's mother had attended a teacher's college; both parents knew Hebrew well before they arrived in Israel and it was the language of their household. Despite his qualifications and skills Dr Engelberg's work life in the young country was no bed of roses.

During the pre-State years he was employed at the Dead Sea works and would be gone from home for extended periods, working in scorching conditions near the Dead Sea while the family lived in the Arnona neighborhood in Jerusalem.

When the company closed in 1948 he found employment in Tel Aviv in small workshops that produced shoe polish and other similar products. However, it was quite common for him to arrive at work and find a notice on the door saying that the manufacturer had ceased production.

He was extremely creative and took out 30 patents in different fields, including one for shoe soles that massage one's feet as one walks, but unfortunately at that time there were no venture capitalists to commercialize his inventions. Many years later he was employed by the Hebrew University Faculty of Agriculture.

In the late 40s, when life on the outskirts of Jerusalem became risky, the family evacuated to Tel Aviv where they shared a dwelling with another family near Jaffa.

Hanna recalls that despite the difficult living conditions – uncertain income, a shared kitchen and facilities – the main concern of her parents was to further their children's education.

Hanna attended the acclaimed Tel Aviv high school, Ironi Aleph, where boys and girls studied in separate classes, and she joined the youth movement with her more affluent classmates. She also played the violin throughout her school years.

Continuing to university after army service was the default choice of her group and Hanna studied at the Hebrew University, supporting herself with summer jobs.

At one stage Hanna considered becoming a doctor, but her mother persuaded her that she would do better as a research scientist and luckily she was open to good advice! (Her younger brother did study medicine, with parental encouragement, and became a surgeon).

After a post-doctoral stint at the Albert Einstein Institute in New York in the early 70s Hanna was awarded a position at the Hebrew University Faculty of Medicine where she continues with her research to this day. She and her sculptor husband, the late Dan Kulka, spent many years enjoying the rich cultural life of Jerusalem.

Ma'ze? Hanna's war on bugs 

The name of the genes Hanna works on says it all – Ma'ze, (what's that ?המ הז) MazeE and MazeF, to be precise, and her driving curiosity keep her vibrantly active long after the official retirement age.

Hanna credits two people who influenced her: her Ph.D. advisor, Dr Artman, who found nothing more stimulating than figuring out weird and unexpected experimental results; and Barbara McClintock, an American scientist who discovered "jumping genes" in the 1940s, findings that were accepted by her male colleagues only 40 years later and for which she was awarded the Nobel prize at the age of 81.

During a visit to Jerusalem, McClintok told Hanna: "It's the experiments that keep one going". Hanna heartily agrees. Hanna's research into MazeEF has resulted in a goldmine of new paradigms for understanding bacteria.

She has also discovered a molecule that leads bacteria to commit suicide, a discovery that will hopefully lead to a new generation of antibiotics, especially against notoriously persistent bacteria such as those that cause TB.

Usually we think of bacteria as individual cells that multiply fast and, when present in large numbers, cause disease. Today we know that bacteria behave very differently when alone and when in a group.

In fact, bacteria are very social, and communicate with one another incessantly. When a bug of a certain type finds itself alone somewhere in the body without any soulmates it keeps a low profile so as not to alert the body's immune system.

However, when these bugs reach a respectable number known as a quorum – maybe 100,000 or so – they act like neighborhood thugs and nothing can stop them.

How do they know they're not alone? They communicate with one another via small molecules; each bug releases a small number of molecules and each one is able to assess how many of these molecules are present in their environment.

Sometimes a high level of danger leads the majority of the population to destroy themselves so that a small number of survivors will maintain the species.

Why would a population of bacteria decide to commit suicide? In his book, The Selfish Gene, Richard Dawkins tells us that our bodies are mere vessels for conveying our genes from one generation to the next.

So imagine a population of identical bacteria after one's doctor has prescribed antibiotics. The stress is unbelievable. How can they prevent being wiped out entirely? Apparently 90% are prepared to die in an effort to preserve a core 10% of the population.

Which bug survives is entirely random – the surviving bacteria have no special qualities. Hanna's characterization of the intricate details of this system, with a young colleague at the University of Vienna, will give scientists the tool for destroying this remaining core of persistent bugs.

There is no doubt that her unflagging curiosity will ensure that Hanna continues to lead the field. 

 

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